Microfluidic chip, and substrate and cover plate used for microfluidic chip

Abstract

The present invention relates to a microfluidic chip comprising at least a substrate that is provided with a flow channel and a cover plate that is joined to the substrate so as to cover the flow channel, wherein: the substrate and the cover plate each comprise a thermoplastic resin; and the thermoplastic resin of at least one of the substrate and the cover plate includes, as a constituent component, a specific block copolymer which includes an amorphous resin segment having an alicyclic structure and a non-cyclic aliphatic low-crystalline resin segment.

Description

Microchannel chip, and substrate and cover plate used in the microchannel chip

[0001] The present invention relates to a microchannel chip, and a substrate and a cover plate used in the microchannel chip.

[0002] In order to mass-produce microchannel chips at low cost, attempts have been made to mold a base plate with a channel and a cover plate using thermoplastic resin, and then join them by heat fusion without using adhesive.

[0003] For example, Patent Document 1 discloses that transparent polyolefin substrates made of olefin-based polymers having a specific polymer chain structure are heat-treated at a temperature below the maximum value of the glass transition temperature Tg and directly bonded together, thereby maintaining the shape of the flow channel. Also, Patent Document 2 discloses that a tightly bonded structure that maintains the shape of the recesses on the bonding surface can be obtained by using a resin composition made of a polypropylene-based resin and a hydrogenated derivative of a block copolymer.

[0004] Japanese Patent Publication No. 2003-220330 Japanese Patent Publication No. 2006-181740

[0005] The present inventors therefore focused on the polymers constituting the thermoplastic resin and their glass transition temperatures (Tg) and melting temperatures (Tm), and found that when joining a substrate having flow channel grooves obtained by molding a thermoplastic resin to a cover plate, thermal fusion can be achieved at a temperature equal to or higher than the glass transition temperature (Tg) for amorphous resins and at a temperature equal to or higher than the melting temperature (Tm) for crystalline resins, achieving high bondability. However, the thermoplastic resin's viscosity drops rapidly, making the flow channel grooves susceptible to collapse even with a small stress, and good shape retention cannot be achieved at the same time.

[0006] Therefore, when joining a substrate with a channel groove to a cover plate by thermal fusion, it is necessary to control the stress and temperature within an extremely narrow range. Microchannel chips that require such control are difficult to produce, or even if they can be produced, the productivity is extremely low.

[0007] Therefore, one object of the present invention is to provide a microchannel chip that can achieve both high bondability during manufacturing and good shape retention of the channel grooves over a wide temperature range, including a low temperature range. Another object of the present invention is to provide a substrate with channel grooves for use in a microchannel chip that can achieve both high bondability to a cover plate and good shape retention of the channel grooves over a wide temperature range, including a low temperature range. Another object of the present invention is to provide a cover plate for use in a microchannel chip that can achieve high bondability to a substrate with channel grooves over a wide temperature range, including a low temperature range.

[0008] As a result of intensive research aimed at solving the above-mentioned problems, the present inventors have found that the above-mentioned problems can be solved by using a thermoplastic resin containing a specific block copolymer that contains, as constituent components, an amorphous resin segment having an alicyclic structure and an acyclic aliphatic low-crystalline resin segment, and have thus completed the present invention.

[0009] That is, the gist of the present invention is as follows. <Aspect 1> A microchannel chip comprising at least a substrate having a flow channel and a cover plate bonded to the substrate so as to cover the flow channel, wherein the substrate and the cover plate are each made of a thermoplastic resin, and the thermoplastic resin of at least one of the substrate and the cover plate contains, as a constituent, a block copolymer (A) that satisfies the following conditions (1-i) to (1-iii): (1-i) The block copolymer (A) contains an amorphous resin segment (A-a) having an alicyclic structure and an acyclic aliphatic low-crystalline resin segment (A-c). (1-ii) The glass transition temperature Tg(A) of the block copolymer (A) is in the range of 50 to 140°C. (1-iii) The glass transition temperature Tg(A) and the melting point Tm(A) of the block copolymer (A) satisfy the relationship of the following formula (1): Formula (1): Tg(A) - Tm(A) ≧ 20°C

[0010] Aspect 1' A substrate having a flow channel, for use in a microchannel chip, comprising a thermoplastic resin, the thermoplastic resin containing, as a constituent, a block copolymer (A)' that satisfies the following conditions (1-i)' to (1-iii)'. (1-i) The block copolymer (A)' contains an amorphous resin segment (A-a)' having an alicyclic structure, and an acyclic aliphatic low-crystalline resin segment (A-c). (1-ii) The glass transition temperature Tg(A)' of the block copolymer (A)' is in the range of 50 to 140°C. (1-iii) The glass transition temperature Tg(A)' and the melting point Tm(A)' of the block copolymer (A)' satisfy the relationship of the following formula (1)'. Formula (1)': Tg(A)' - Tm(A)' ≧ 20°C

[0011] Aspect 1″ is a cover plate for use in a micro-channel chip, the cover plate being bonded to a substrate having a channel groove so as to cover the substrate, the cover plate being made of a thermoplastic resin, the thermoplastic resin containing, as a constituent, a block copolymer (A)″ that satisfies the following conditions (1-i)″ to (1-iii)″. (1-i)″ The block copolymer (A)″ contains an amorphous resin segment (A-a)″ having an alicyclic structure, and an acyclic aliphatic low-crystalline resin segment (A-c)″. (1-ii)″ The glass transition temperature Tg(A)″ of the block copolymer (A)″ is in the range of 50 to 140°C. (1-iii)″ The glass transition temperature Tg(A)″ and the melting point Tm(A)″ of the block copolymer (A)″ satisfy the relationship of the following formula (1)″. Formula (1)″: Tg(A)″-Tm(A)″≧20°C

[0012] Aspect 2: A micro-channel chip comprising at least a substrate having a flow channel and a cover plate bonded to the substrate so as to cover the flow channel, wherein the substrate and the cover plate are each made of a thermoplastic resin, and the thermoplastic resin of at least one of the substrate and the cover plate contains, as constituent components, a block copolymer (A1) and a block copolymer (A2) that satisfy the following conditions (2-i) to (2-iv): (2-i) The block copolymer (A1) contains an amorphous resin segment (A1-a) having an alicyclic structure and an acyclic aliphatic low-crystalline resin segment (A1-c), and the block copolymer (A2) contains an amorphous resin segment (A2-a) having an alicyclic structure and an acyclic aliphatic low-crystalline resin segment (A2-c). (2-ii) The glass transition temperature Tg(A1) of the block copolymer (A1) and the glass transition temperature Tg(A2) of the block copolymer (A2) are each in the range of 50 to 140°C. (2-iii) The glass transition temperature Tg(A1) and melting point Tm(A1) of the block copolymer (A1), and the glass transition temperature Tg(A2) and melting point Tm(A2) of the block copolymer (A2) satisfy the relationship of the following formula (2-1): Formula (2-1): Tg(A1) - Tm(A1) ≧ 20°C, and Tg(A2) - Tm(A2) ≧ 20°C (2-iv) The glass transition temperature Tg(A1) of the block copolymer (A1) and the glass transition temperature Tg(A2) of the block copolymer (A2) satisfy the relationship of the following formula (2-2): Formula (2-2): Tg(A1) - Tg(A2) ≧ 5°C

[0013] Aspect 2': A substrate having a flow channel, for use in a microchannel chip, comprising a thermoplastic resin, the thermoplastic resin containing, as constituent components, a block copolymer (A1)' and a block copolymer (A2)' that satisfy the following conditions (2-i)' to (2-iv): (2-i) The block copolymer (A1)' contains an amorphous resin segment (A1-a)' having an alicyclic structure and an acyclic aliphatic low-crystalline resin segment (A1-c)', and the block copolymer (A2)' contains an amorphous resin segment (A2-a)' having an alicyclic structure and an acyclic aliphatic low-crystalline resin segment (A2-c)'. (2-ii) The glass transition temperature Tg(A1)' of the block copolymer (A1)' and the glass transition temperature Tg(A2)' of the block copolymer (A2)' are each in the range of 50 to 140°C. (2-iii) The glass transition temperature Tg(A1)' and melting point Tm(A1)' of the block copolymer (A1)', and the glass transition temperature Tg(A2)' and melting point Tm(A2)' of the block copolymer (A2)' satisfy the relationship of the following formula (2-1)'. Formula (2-1)': Tg(A1)'-Tm(A1)'≧20°C, and Tg(A2)'-Tm(A2)'≧20°C. (2-iv) The glass transition temperature Tg(A1)' of the block copolymer (A1)' and the glass transition temperature Tg(A2)' of the block copolymer (A2)' satisfy the relationship of the following formula (2-2)'. Formula (2-2)': Tg(A1)'-Tg(A2)'≧5°C.

[0014] Aspect 2″ is a cover plate for use in a micro-channel chip, the cover plate being bonded to a substrate having a channel groove so as to cover the substrate, the cover plate being made of a thermoplastic resin, the thermoplastic resin containing, as constituent components, a block copolymer (A1)″ and a block copolymer (A2)″ that satisfy the following conditions (2-i)″ to (2-iv)′″: (2-i)″ the block copolymer (A1)″ comprises an amorphous resin segment (A1-a)″ having an alicyclic structure and an acyclic aliphatic low-crystalline resin segment (A1-c)″, and the block copolymer (A2)″ comprises an amorphous resin segment (A2-a)″ having an alicyclic structure and an acyclic aliphatic low-crystalline resin segment (A2-c)″. (2-ii) The glass transition temperature Tg(A1)'' of the block copolymer (A1)'' and the glass transition temperature Tg(A2)'' of the block copolymer (A2)'' are each in the range of 50 to 140°C. (2-iii) The glass transition temperature Tg(A1)'' and the melting point Tm(A1)'' of the block copolymer (A1)'' and the glass transition temperature Tg(A2)'' and the melting point Tm(A2)'' of the block copolymer (A2)'' satisfy the relationship of the following formula (2-1)''. Formula (2-1)": Tg(A1)"-Tm(A1)"≧20°C, and Tg(A2)"-Tm(A2)"≧20°C. (2-iv)" The glass transition temperature Tg(A1)" of the block copolymer (A1)" and the glass transition temperature Tg(A2)" of the block copolymer (A2)" satisfy the relationship of the following formula (2-2)". Formula (2-2)": Tg(A1)"-Tg(A2)"≧5°C.

[0015] Aspect 3: A micro-channel chip comprising at least a substrate having a flow channel and a cover plate bonded to the substrate so as to cover the flow channel, wherein the substrate and the cover plate are each made of a thermoplastic resin, and the thermoplastic resin of at least one of the substrate and the cover plate is composed of a block copolymer (A) and a block copolymer (B) that satisfy the following conditions (3-i) to (3-v): (3-i) The block copolymer (A) contains an amorphous resin segment (A-a) having an alicyclic structure and an acyclic aliphatic low-crystalline resin segment (A-c). (3-ii) The glass transition temperature Tg(A) of the block copolymer (A) is in the range of 50 to 140°C. (3-iii) The glass transition temperature Tg(A) and the melting point Tm(A) of the block copolymer (A) satisfy the relationship of the following formula (3-1). Formula (3-1): Tg(A) - Tm(A) ≧ 20°C. (3-iv) The block copolymer (B) contains an amorphous resin segment (Ba) having an aromatic hydrocarbon structure and an acyclic aliphatic low-crystalline resin segment (Bc). (3-v) The glass transition temperature Tg(A) of the block copolymer (A) and the glass transition temperature Tg(B) of the block copolymer (B) satisfy the relationship of the following formula (3-2): Formula (3-2): Tg(A) - Tg(B) ≧ 10°C.

[0016] Aspect 3' A substrate having a flow channel, for use in a microchannel chip, comprising a thermoplastic resin, the thermoplastic resin containing, as constituent components, a block copolymer (A)' and a block copolymer (B)' that satisfy the following conditions (3-i)' to (3-v)': (3-i) The block copolymer (A)' contains an amorphous resin segment (A-a)' having an alicyclic structure, and an acyclic aliphatic low-crystalline resin segment (A-c)'. (3-ii) The block copolymer (A)' has a glass transition temperature Tg(A)' in the range of 50 to 140°C. (3-iii) The glass transition temperature Tg(A)' and the melting point Tm(A)' of the block copolymer (A)' satisfy the relationship of the following formula (3-1)': Formula (3-1)': Tg(A)'-Tm(A)'≧20°C. (3-iv)' The block copolymer (B)' comprises an amorphous resin segment (Ba)' having an aromatic hydrocarbon structure, and an acyclic aliphatic low-crystalline resin segment (B-c)'. (3-v)' The glass transition temperature Tg(A)' of the block copolymer (A)' and the glass transition temperature Tg(B)' of the block copolymer (B)' satisfy the relationship of the following formula (3-2)'. Formula (3-2)': Tg(A)'-Tg(B)'≧10°C.

[0017] Aspect 3'' A cover plate for use in a micro-channel chip, the cover plate being bonded to a substrate having a channel groove so as to cover the substrate, the cover plate being made of a thermoplastic resin, the thermoplastic resin containing, as constituent components, a block copolymer (A)'' and a block copolymer (B)'' that satisfy the following conditions (3-i)'' to (3-v)''. (3-i)'' The block copolymer (A)'' contains an amorphous resin segment (A-a)'' having an alicyclic structure, and an acyclic aliphatic low-crystalline resin segment (A-c)''. (3-ii)'' The block copolymer (A)'' has a glass transition temperature Tg(A)'' in the range of 50 to 140°C. (3-iii)'' The glass transition temperature Tg(A)'' and the melting point Tm(A)'' of the block copolymer (A)'' satisfy the relationship of the following formula (3-1)''. Formula (3-1)': Tg(A)'-Tm(A)'≧20°C. (3-iv)'The block copolymer (B)' comprises an amorphous resin segment (B-a)' having an aromatic hydrocarbon structure and an acyclic aliphatic low-crystalline resin segment (B-c)'. (3-v)'The glass transition temperature Tg(A)' of the block copolymer (A)' and the glass transition temperature Tg(B)' of the block copolymer (B)' satisfy the relationship of the following formula (3-2)'. Formula (3-2)': Tg(A)'-Tg(B)'≧10°C.

[0018] Aspect 4: A micro-channel chip comprising at least a substrate having a flow channel and a cover plate bonded to the substrate so as to cover the flow channel, wherein the substrate and the cover plate are each made of a thermoplastic resin, and the thermoplastic resin of at least one of the substrate and the cover plate contains, as constituent components, a block copolymer (A1), a block copolymer (A2), and a block copolymer (B) that satisfy the following conditions (4-i) to (4-vi): (4-i) The block copolymer (A1) contains an amorphous resin segment (A1-a) having an alicyclic structure and an acyclic aliphatic low-crystalline resin segment (A1-c), and the block copolymer (A2) contains an amorphous resin segment (A2-a) having an alicyclic structure and an acyclic aliphatic low-crystalline resin segment (A2-c). (4-ii) The glass transition temperature Tg(A1) of the block copolymer (A1) and the glass transition temperature Tg(A2) of the block copolymer (A2) are each in the range of 50 to 140° C. (4-iii) The glass transition temperature Tg(A1) and the melting point Tm(A1) of the block copolymer (A1), and the glass transition temperature Tg(A2) and the melting point Tm(A2) of the block copolymer (A2) satisfy the relationship of the following formula (4-1): Formula (4-1): Tg(A1) - Tm(A1) ≧ 20° C., and Tg(A2) - Tm(A2) ≧ 20° C. (4-iv) The glass transition temperature Tg(A1) of the block copolymer (A1) and the glass transition temperature Tg(A2) of the block copolymer (A2) satisfy the relationship of the following formula (4-2). Formula (4-2): Tg(A1) - Tg(A2) ≧ 5°C. (4-v) The block copolymer (B) contains an amorphous resin segment (Ba) having an aromatic hydrocarbon structure and an acyclic aliphatic low-crystalline resin segment (B-c). (4-vi) The glass transition temperature Tg(A2) of the block copolymer (A2) and the glass transition temperature Tg(B) of the block copolymer (B) satisfy the relationship of the following formula (4-3): Formula (4-3): Tg(A2) - Tg(B) ≧ 10°C.

[0019] Aspect 4' A substrate having a flow channel for use in a microchannel chip, the substrate being made of a thermoplastic resin, the thermoplastic resin containing, as constituent components, a block copolymer (A1)', a block copolymer (A2)', and a block copolymer (B)' that satisfy the following conditions (4-i)' to (4-vi): (4-i) The block copolymer (A1)' contains an amorphous resin segment (A1-a)' having an alicyclic structure and an acyclic aliphatic low-crystalline resin segment (A1-c)', and the block copolymer (A2)' contains an amorphous resin segment (A2-a)' having an alicyclic structure and an acyclic aliphatic low-crystalline resin segment (A2-c)'. (4-ii) The glass transition temperature Tg(A1)' of the block copolymer (A1)' and the glass transition temperature Tg(A2)' of the block copolymer (A2)' are each in the range of 50 to 140°C. (4-iii) The glass transition temperature Tg(A1)' and melting point Tm(A1)' of the block copolymer (A1)', and the glass transition temperature Tg(A2)' and melting point Tm(A2)' of the block copolymer (A2)' satisfy the relationship of the following formula (4-1)': Formula (4-1)': Tg(A1)'-Tm(A1)'≧20°C, and Tg(A2)'-Tm(A2)'≧20°C. (4-iv) The glass transition temperature Tg(A1)' of the block copolymer (A1)' and the glass transition temperature Tg(A2)' of the block copolymer (A2)' satisfy the relationship of the following formula (4-2)'. Formula (4-2)': Tg(A1)'-Tg(A2)'≧5°C. (4-v)' The block copolymer (B)' comprises an amorphous resin segment (Ba)' having an aromatic hydrocarbon structure, and an acyclic aliphatic low-crystalline resin segment (B-c)'. (4-vi)' The glass transition temperature Tg(A2)' of the block copolymer (A2)' and the glass transition temperature Tg(B)' of the block copolymer (B)' satisfy the relationship of the following formula (4-3)'. Formula (4-3)': Tg(A2)'-Tg(B)'≧10°C.

[0020] Aspect 4'' A cover plate for use in a micro-channel chip, the cover plate being bonded to a substrate having a channel groove so as to cover the substrate, the cover plate being made of a thermoplastic resin, the thermoplastic resin containing, as constituent components, a block copolymer (A1)'', a block copolymer (A2)'', and a block copolymer (B)'', which satisfy the following conditions (4-i)'' to (4-vi)'': (4-i)'' The block copolymer (A1)'' contains an amorphous resin segment (A1-a)'' having an alicyclic structure and an acyclic aliphatic low-crystalline resin segment (A1-c)'', and the block copolymer (A2)'' contains an amorphous resin segment (A2-a)'' having an alicyclic structure and an acyclic aliphatic low-crystalline resin segment (A2-c)''. (4-ii) The glass transition temperature Tg(A1)'' of the block copolymer (A1)'' and the glass transition temperature Tg(A2)'' of the block copolymer (A2)'' are each in the range of 50 to 140°C. (4-iii) The glass transition temperature Tg(A1)'' and the melting point Tm(A1)'' of the block copolymer (A1)'' and the glass transition temperature Tg(A2)'' and the melting point Tm(A2)'' of the block copolymer (A2)'' satisfy the relationship of the following formula (4-1)''. Formula (4-1)": Tg(A1)"-Tm(A1)"≧20°C, and Tg(A2)"-Tm(A2)"≧20°C. (4-iv)" The glass transition temperature Tg(A1)" of the block copolymer (A1)" and the glass transition temperature Tg(A2)" of the block copolymer (A2)" satisfy the relationship of the following formula (4-2)". Formula (4-2)": Tg(A1)"-Tg(A2)"≧5°C. (4-v)" The block copolymer (B)" comprises an amorphous resin segment (Ba)" having an aromatic hydrocarbon structure, and an acyclic aliphatic low-crystalline resin segment (B-c)". (4-vi) The glass transition temperature Tg(A2)'' of the block copolymer (A2)'' and the glass transition temperature Tg(B)'' of the block copolymer (B)'' satisfy the relationship of the following formula (4-3)''. Formula (4-3)'': Tg(A2)''-Tg(B)''≧10°C

[0021] <Aspect 5> The micro-channel chip according to <Aspect 2> or <Aspect 4>, wherein the block copolymer (A1) and the block copolymer (A2) further satisfy the following condition (5): (5) The amorphous resin segment (A1-a) having an alicyclic structure and the amorphous resin segment (A2-a) having an alicyclic structure are each a vinylcyclohexane-based polymer, and the acyclic aliphatic low-crystalline resin segment (A1-c) and the acyclic aliphatic low-crystalline resin segment (A2-c) are each an ethylene-butene copolymer.

[0022] Aspect 6: The micro-channel chip according to Aspect 3 or Aspect 4, wherein the block copolymer (B) further satisfies the following condition (6): (6) The amorphous resin segment (Ba) having an aromatic hydrocarbon structure is a styrene-based polymer, and the acyclic aliphatic low-crystalline resin segment (Bc) is an ethylene-butene copolymer.

[0023] The present invention makes it possible to provide a microchannel chip that can achieve both high bondability during manufacturing and good shape retention of the channel grooves over a wide temperature range, including a low temperature range. As a result, the stress and temperature can be controlled over a wider range when heat-sealing a substrate with channel grooves to a cover plate, thereby achieving good productivity. The present invention also makes it possible to provide a substrate with channel grooves for use in a microchannel chip that can achieve both high bondability to the cover plate and good shape retention of the channel grooves over a wide temperature range, including a low temperature range. As a result, the stress and temperature can be controlled over a wider range when heat-sealing the substrate with the cover plate, thereby achieving good productivity. The present invention also makes it possible to provide a cover plate for use in a microchannel chip that can achieve high bondability to a substrate with channel grooves over a wide temperature range, including a low temperature range. As a result, the stress and temperature can be controlled over a wider range when heat-sealing the substrate with channel grooves to a cover plate, thereby achieving good productivity.

[0024] The following describes in detail an embodiment of the present invention, but the following embodiment is an example of an embodiment of the present invention, and the present invention is not limited to these descriptions. The present invention can be implemented by any modification within the scope of the gist of the present invention. In this specification, when a numerical value or physical property value is enclosed before and after "~", the value before and after the "~" is used and is used as including the values ​​before and after the "~". In this specification, mass % and weight % have the same meaning.

[0025] The micro-channel chip according to this embodiment includes at least a substrate having a channel and a cover plate bonded to the substrate so as to cover the channel. The substrate and the cover plate are preferably made of a thermoplastic resin.

[0026] In a first aspect of the micro-channel chip according to the present embodiment, the thermoplastic resin of at least one of the substrate and cover plate contains, as a constituent component, a block copolymer (A) that satisfies the following conditions (1-i) to (1-iii):

[0027] (1-i) The block copolymer (A) contains an amorphous resin segment (A-a) having an alicyclic structure and an acyclic aliphatic low-crystalline resin segment (Ac). (1-ii) The glass transition temperature Tg(A) of the block copolymer (A) is in the range of 50 to 140°C. (1-iii) The glass transition temperature Tg(A) and the melting point Tm(A) of the block copolymer (A) satisfy the relationship of the following formula (1): Formula (1): Tg(A) - Tm(A) ≧ 20°C

[0028] The block copolymer (A) preferably consists of a block copolymer (A1) and a block copolymer (A2) that satisfy the following conditions (2-i) to (2-iv): That is, in a second aspect of the micro-channel chip according to the present embodiment, the thermoplastic resin of at least one of the substrate and the cover plate preferably contains, as constituent components, a block copolymer (A1) and a block copolymer (A2) that satisfy the following conditions (2-i) to (2-iv):

[0029] (2-i) The block copolymer (A1) contains an amorphous resin segment (A1-a) having an alicyclic structure and an acyclic aliphatic low-crystalline resin segment (A1-c), and the block copolymer (A2) contains an amorphous resin segment (A2-a) having an alicyclic structure and an acyclic aliphatic low-crystalline resin segment (A2-c). (2-ii) The glass transition temperature Tg(A1) of the block copolymer (A1) and the glass transition temperature Tg(A2) of the block copolymer (A2) are each in the range of 50 to 140°C. (2-iii) The glass transition temperature Tg(A1) and the melting point Tm(A1) of the block copolymer (A1), and the glass transition temperature Tg(A2) and the melting point Tm(A2) of the block copolymer (A2) satisfy the relationship of the following formula (2-1): Formula (2-1): Tg(A1) - Tm(A1) ≧ 20°C and Tg(A2) - Tm(A2) ≧ 20°C (2-iv) The glass transition temperature Tg(A1) of the block copolymer (A1) and the glass transition temperature Tg(A2) of the block copolymer (A2) satisfy the relationship of the following formula (2-2): Formula (2-2): Tg(A1) - Tg(A2) ≧ 5°C

[0030] In a third aspect of the micro-channel chip according to the present embodiment, the thermoplastic resin of at least one of the substrate and the cover plate contains, as constituent components, a block copolymer (A) and a block copolymer (B) that satisfy the following conditions (3-i) to (3-v):

[0031] (3-i) The block copolymer (A) comprises an amorphous resin segment (A-a) having an alicyclic structure and an acyclic aliphatic low-crystalline resin segment (A-c). (3-ii) The glass transition temperature Tg(A) of the block copolymer (A) is in the range of 50 to 140°C. (3-iii) The glass transition temperature Tg(A) and the melting point Tm(A) of the block copolymer (A) satisfy the relationship of the following formula (3-1): Formula (3-1): Tg(A) - Tm(A) ≧ 20°C. (3-iv) The block copolymer (B) comprises an amorphous resin segment (B-a) having an aromatic hydrocarbon structure and an acyclic aliphatic low-crystalline resin segment (B-c). (3-v) The glass transition temperature Tg(A) of the block copolymer (A) and the glass transition temperature Tg(B) of the block copolymer (B) satisfy the relationship of the following formula (3-2). Formula (3-2): Tg(A)-Tg(B)≧10°C or more

[0032] In a fourth aspect of the micro-channel chip according to the present embodiment, the thermoplastic resin of at least one of the substrate and the cover plate contains, as constituent components, a block copolymer (A1), a block copolymer (A2), and a block copolymer (B), which satisfy the following conditions (4-i) to (4-vi):

[0033] (4-i) The block copolymer (A1) contains an amorphous resin segment (A1-a) having an alicyclic structure and an acyclic aliphatic low-crystalline resin segment (A1-c), and the block copolymer (A2) contains an amorphous resin segment (A2-a) having an alicyclic structure and an acyclic aliphatic low-crystalline resin segment (A2-c). (4-ii) The glass transition temperature Tg(A1) of the block copolymer (A1) and the glass transition temperature Tg(A2) of the block copolymer (A2) are each in the range of 50 to 140°C. (4-iii) The glass transition temperature Tg(A1) and the melting point Tm(A1) of the block copolymer (A1), and the glass transition temperature Tg(A2) and the melting point Tm(A2) of the block copolymer (A2) satisfy the relationship of the following formula (4-1): Formula (4-1): Tg(A1) - Tm(A1) ≧ 20°C, and Tg(A2) - Tm(A2) ≧ 20°C. (4-iv) The glass transition temperature Tg(A1) of the block copolymer (A1) and the glass transition temperature Tg(A2) of the block copolymer (A2) satisfy the relationship of the following formula (4-2): Formula (4-2): Tg(A1) - Tg(A2) ≧ 5°C. (4-v) The block copolymer (B) contains an amorphous resin segment (B-a) having an aromatic hydrocarbon structure and an acyclic aliphatic low-crystalline resin segment (B-c). (4-vi) The glass transition temperature Tg(A2) of the block copolymer (A2) and the glass transition temperature Tg(B) of the block copolymer (B) satisfy the relationship of the following formula (4-3): Formula (4-3): Tg(A2) - Tg(B) ≧ 10°C.

[0034] In the second and fourth aspects, it is preferable that the block copolymer (A1) and the block copolymer (A2) further satisfy the following condition (5):

[0035] (5) The amorphous resin segment (A1-a) having an alicyclic structure and the amorphous resin segment (A2-a) having an alicyclic structure are each a vinylcyclohexane-based polymer, and the acyclic aliphatic low-crystalline resin segment (A1-c) and the acyclic aliphatic low-crystalline resin segment (A2-c) are each an ethylene-butene copolymer.

[0036] In the third and fourth aspects, it is preferable that the block copolymer (B) further satisfies the following condition (6):

[0037] (6) In the block copolymer (B), the amorphous resin segment (Ba) having an aromatic hydrocarbon structure is a styrene-based polymer, and the acyclic aliphatic low-crystalline resin segment (Bc) is an ethylene-butene copolymer.

[0038] <<Thermoplastic Resin>> <Block Copolymer (A) ((A1), (A2))> In one aspect of the micro-channel chip according to the present embodiment, the thermoplastic resin of at least one of the substrate having a channel groove and the cover plate bonded thereto contains a specific block copolymer (A) as a constituent component. The block copolymer (A) satisfies the following conditions (1-i) to (1-iii) (first aspect):

[0039] (1-i) The block copolymer (A) contains an amorphous resin segment (A-a) having an alicyclic structure and an acyclic aliphatic low-crystalline resin segment (Ac). (1-ii) The glass transition temperature Tg(A) of the block copolymer (A) is in the range of 50 to 140°C. (1-iii) The glass transition temperature Tg(A) and the melting point Tm(A) of the block copolymer (A) satisfy the relationship of the following formula (1): Formula (1): Tg(A) - Tm(A) ≧ 20°C

[0040] As required by the above condition (1-i), the block copolymer (A) contains an amorphous resin segment (A-a) having an alicyclic structure and an acyclic aliphatic low-crystalline resin segment (A-c). As described above, the block copolymer (A) is composed of a block copolymer having a structure in which two or more types of polymer chains (segments) with different properties are linked together. This allows for high bondability to be achieved without damaging the fine shape of the flow channel in the substrate when the substrate and cover plate are bonded by thermal fusion.

[0041] When the micro-channel chip according to this embodiment is the second embodiment, the block copolymer (A) constituting the thermoplastic resin is composed of a block copolymer (A1) and a block copolymer (A2). In this case, the block copolymer (A1) and the block copolymer (A2) are the same as the above-described block copolymer (A), but are different from each other.

[0042] In this way, the micro-channel chip according to this embodiment may use a combination of two or more types of block copolymer (A) constituting the thermoplastic resin.

[0043] That is, when the thermoplastic resin of the micro-channel chip according to this embodiment contains block copolymers (A1) and (A2) as block copolymers as constituent components, block copolymer (A1) contains an amorphous resin segment (A1-a) having an alicyclic structure and an acyclic aliphatic low-crystalline resin segment (A1-c), and block copolymer (A2) contains an amorphous resin segment (A2-a) having an alicyclic structure and an acyclic aliphatic low-crystalline resin segment (A2-c) (condition 2-i).

[0044] From the viewpoint of good compatibility and high transparency, it is preferable that the two or more block copolymers to be combined have substantially the same skeletal structure. Here, "the same skeletal structure of the block copolymers" means that the atomic arrangement of the constituent units is the same, and "substantially the same" means that the geometric atomic arrangement of the constituent units of the block copolymers is about 90% or more the same. That is, the geometric atomic arrangement of the constituent units of the two or more block copolymers to be combined is preferably about 90% or more the same, may be about 95% or more the same, or may be 100%, i.e., completely the same. Furthermore, as long as the skeletal structures of the two or more block copolymers are substantially the same, the molecular weights (degrees of polymerization) of the blocks may be different.

[0045] Furthermore, from the viewpoint of widening the temperature range in which high bondability and good shape retention of the flow channel can be achieved when fabricating a microchannel chip, it is preferable to combine two or more types of block copolymers having different glass transition temperatures.

[0046] Specifically, the glass transition temperature Tg(A1) of block copolymer (A1) and the glass transition temperature Tg(A2) of block copolymer (A2) preferably differ, and the difference is more preferably 5° C. or more. That is, it is more preferable that the two glass transition temperatures satisfy the relationship of the following formula (2-2) (condition 2-iv): Formula (2-2): Tg(A1) - Tg(A2) ≧ 5° C. Here, of block copolymer (A1) and block copolymer (A2), the one having the higher glass transition temperature is defined as block copolymer (A1).

[0047] The difference between the glass transition temperature Tg(A1) and the glass transition temperature Tg(A2) is more preferably 10° C. or more. There is no particular upper limit to the difference, but it is, for example, 100° C. or less.

[0048] Amorphous resin segment (A-a) ((A1-a), (A2-a)) The amorphous resin segment (A-a) in this embodiment has an alicyclic structure. The amorphous resin segment (A-a) provides the block copolymer (A) with heat resistance, suppresses deformation during heat fusion bonding for bonding, and achieves high transparency.

[0049] The glass transition temperature of the amorphous resin segment (Aa) in this embodiment is 50 to 140° C., and preferably 70 to 125° C. That is, the glass transition temperature Tg(A) of the block copolymer (A) in this embodiment is in the range of 50 to 140° C., and preferably 70 to 125° C.

[0050] When the block copolymer (A) contains multiple amorphous resin segments, the block copolymer (A) may have multiple glass transition temperatures. In such cases, in the present invention, as described below, the glass transition temperature Tg is defined as the highest peak temperature at which a peak of loss modulus G" is observed in solid viscoelasticity measurement (DMA; Dynamic Mechanical Analysis). That is, it is sufficient that the highest peak temperature of loss modulus G" observed in the block copolymer (A) is in the range of 50 to 140°C, and this does not exclude cases where the block copolymer (A) has other glass transition temperatures below 50°C.

[0051] The glass transition temperature of the amorphous resin segment (A-a) in this embodiment is 50°C or higher, and preferably 70°C or higher, from the viewpoint of heat resistance. Furthermore, from the viewpoint of lowering the heat fusion temperature when joining the substrate and the cover plate and from the viewpoint of moldability at low temperatures, the glass transition temperature is 140°C or lower, preferably 135°C or lower, more preferably 130°C or lower, and even more preferably 125°C or lower. That is, the glass transition temperature Tg(A) of the block copolymer (A) in this embodiment is at least in the range of 50°C or higher, and preferably in the range of 70°C or higher, and is also in the range of 140°C or lower, preferably in the range of 135°C or lower, more preferably in the range of 130°C or lower, and even more preferably in the range of 125°C or lower.

[0052] In this specification, the glass transition temperature Tg is the peak temperature of the loss modulus G'' in solid viscoelasticity measurement (DMA; Dynamic Mechanical Analysis), and the measurement was carried out under the following conditions. When multiple peaks of the loss modulus G'' are observed, the highest peak temperature is taken as the glass transition temperature Tg. Measurement mode: Torsion Heating rate: 2°C / min Frequency: 1 Hz Strain: 0.5%

[0053] In the second aspect of the micro-channel chip according to the present embodiment, the amorphous resin segment (A1-a) contained in the block copolymer (A1) has a glass transition temperature of 50 to 140° C. Furthermore, the amorphous resin segment (A2-a) contained in the block copolymer (A2) has a glass transition temperature of 50 to 140° C. This satisfies the condition (2-ii) that the glass transition temperatures Tg(A1) and Tg(A2) of the block copolymer (A1) and the block copolymer (A2), respectively, are in the range of 50 to 140° C.

[0054] Examples of the amorphous resin segment (A-a), amorphous resin segment (A1-a), and amorphous resin segment (A2-a) having an alicyclic structure in the present embodiment include (a) norbornene-based polymers, (b) cyclic olefin-based polymers, and (c) vinyl alicyclic hydrocarbon-based polymers.

[0055] Examples of the (a) norbornene-based polymer include ring-opening polymers of norbornene-based monomers (and other copolymerizable monomers), addition polymers of norbornene-based monomers (and other copolymerizable monomers), and hydrogenated products thereof.

[0056] Examples of the (b) cyclic olefin polymer include addition polymers of monocyclic olefin monomers such as cyclohexene, cycloheptene, and cyclooctene (and other copolymerizable monomers), polymers obtained by 1,2-addition polymerization or 1,4-addition polymerization of cyclic conjugated dienes such as cyclopentadiene and cyclohexadiene (and other copolymerizable monomers), and hydrogenated products thereof.

[0057] Examples of the (c) vinyl alicyclic hydrocarbon polymer include polymers of alicyclic vinyl monomers such as vinylcyclohexane (and other copolymerizable monomers), and hydrogenated products of the aromatic ring moieties of polymers of aromatic vinyl monomers such as styrene and α-methylstyrene (and other copolymerizable monomers). When the (c) vinyl alicyclic hydrocarbon polymer is a copolymer, it may be a random copolymer and / or a block copolymer. Among alicyclic vinyl monomers, polymers such as vinylcyclohexane also fall under the category of hydrogenated products of the aromatic ring moieties of aromatic vinyl monomer polymers.

[0058] Among these, (c) vinyl alicyclic hydrocarbon polymers are preferred as the amorphous resin segment, with vinylcyclohexane polymers being more preferred, from the viewpoints of heat resistance and heat fusion properties.

[0059] Among the vinyl alicyclic hydrocarbon polymers (c) above, examples of aromatic vinyl monomers include styrene, α-methylstyrene, vinyltoluene (including all isomers, particularly p-vinyltoluene), ethylstyrene, propylstyrene, butylstyrene, vinylbiphenyl, vinylnaphthalene, vinylanthracene (all isomers), and mixtures thereof.

[0060] In this case, the higher the hydrogenation level of the unsaturated carbon ring portion of the alicyclic vinyl monomer or the aromatic ring portion of the aromatic vinyl monomer, the higher the glass transition temperature Tg(A). As a result, in the third and fourth aspects of the micro-channel chip according to this embodiment, it is easier to achieve a difference from the glass transition temperature Tg(B) of the block copolymer (B) constituting the thermoplastic resin, widening the range in which high bondability during micro-channel chip production and good shape retention of the channel grooves can be achieved. Additionally, the higher the hydrogenation level, the lower the autofluorescence, making it suitable for use in cases where ultraviolet light is used for analysis, observation, etc.

[0061] From the above viewpoint, the hydrogenation level of the carbon ring moiety or aromatic ring moiety is preferably 90% or more, more preferably 95% or more, and even more preferably 98% or more. There is no particular upper limit, and it may be 100%.

[0062] In this specification, the hydrogenation level refers to the percentage (%) of the number of structures in which the carbocyclic or aromatic ring moiety has been hydrogenated relative to the number of the original carbocyclic or aromatic ring moieties, and the number of the original carbocyclic or aromatic ring moieties refers to the sum of the number of structures in which the carbocyclic or aromatic ring moiety has not been hydrogenated and the number of structures in which the carbocyclic or aromatic ring moiety has been hydrogenated. These numbers are determined by proton NMR (proton nuclear magnetic resonance). Given the limitations of the proton NMR instrument, if the hydrogenation level is 99% or higher, it can be considered to be 100%.

[0063] In the second aspect of the micro-channel chip according to the present embodiment, an example of a combination of the amorphous resin segment (A1-a) and the amorphous resin segment (A2-a) is, for example, a combination in which the amorphous resin segment (A1-a) and the amorphous resin segment (A2-a) are each (c) a vinyl alicyclic hydrocarbon-based polymer, but the combination is not limited to this.

[0064] When the amorphous resin segment (A1-a) and the amorphous resin segment (A2-a) are each (c) a vinyl alicyclic hydrocarbon polymer, it is more preferable that the amorphous resin segment (A1-a) and the amorphous resin segment (A2-a) are each a vinylcyclohexane polymer.

[0065] Low-Crystalline Resin Segment (Ac) ((A1-c), (A2-c)) The low-crystalline resin segment (Ac) in this embodiment is an acyclic aliphatic low-crystalline resin segment, and its melting point is lower than the glass transition temperature of the amorphous resin segment (A-a). That is, the melting point Tm(A) of the block copolymer (A) in this embodiment is lower than the glass transition temperature Tg(A). That is, the glass transition temperature Tg(A) and the melting point Tm(A) of the block copolymer (A) have the relationship Tg(A) > Tm(A).

[0066] Here, when the block copolymer (A) contains a plurality of low-crystalline resin segments, the block copolymer (A) may exhibit a plurality of melting points. In such a case, in the present invention, as will be described later, a plurality of endothermic peaks are observed in the measurement using a differential scanning calorimeter (DSC), and the peak temperature of the largest peak among them is taken as the melting point Tm. In other words, the block copolymer (A) may have an endothermic peak in a temperature range higher than the glass transition temperature Tg(A), as long as the largest endothermic peak is lower than the glass transition temperature Tg(A). This does not exclude the case where the block copolymer (A) has an endothermic peak in a temperature range higher than the glass transition temperature Tg(A).

[0067] In this embodiment, the glass transition temperature Tg(A) and the melting point Tm(A) of the block copolymer (A) satisfy the relationship Tg(A)>Tm(A), and therefore, when a microchannel chip is obtained, both high bondability and good shape retention of the channel groove can be achieved.

[0068] In this embodiment, the acyclic aliphatic low-crystalline resin segment (A-c) may be linear or branched, but preferably has low crystallinity in order to satisfy the relationship between the glass transition temperature Tg(A) and the melting point Tm(A). This is because too high crystallinity results in poor heat fusion and reduced transparency. Here, low crystallinity means that the latent heat upon melting is 30 mJ / mg or less in DSC measurement.

[0069] As described above, the glass transition temperature Tg(A) and the melting point Tm(A) of the block copolymer (A) in this embodiment have the relationship Tg(A) > Tm(A), but the difference is 20°C or more. That is, the glass transition temperature Tg(A) and the melting point Tm(A) satisfy the relationship of the following formula (1) (condition 1-iii): Formula (1): Tg(A) - Tm(A) ≥ 20°C

[0070] By satisfying the relationship of the above formula (1), a wide temperature range can be realized in which sufficient sealing strength can be obtained without damaging the channel shape when manufacturing a microchannel chip. The difference between the glass transition temperature Tg(A) and the melting point Tm(A) may be 20°C or more, but is preferably 30°C or more. The upper limit of the difference is not particularly limited, but is, for example, 110°C or less.

[0071] The melting point Tm(A) of the block copolymer (A) in this embodiment is preferably 30 to 100° C., more preferably 40 to 90° C. From the viewpoint of heat resistance of the flow path, the melting point Tm(A) is preferably 30° C. or higher, more preferably 40° C. or higher. Furthermore, from the viewpoint of low-temperature fusion properties, the melting point Tm(A) is preferably 100° C. or lower, more preferably 90° C. or lower.

[0072] In this specification, the melting point Tm is the endothermic peak temperature when a sample is once heated to 200°C in a differential scanning calorimeter (DSC) to melt, cooled to -60°C at a cooling rate of 10°C / min, and then heated again at a rate of 10°C / min. When multiple endothermic peaks are observed, the peak temperature of the largest peak is taken as the melting point Tm.

[0073] In view of the productivity of the block copolymer (A), the acyclic aliphatic low-crystalline resin segment (Ac) in this embodiment is preferably a block obtained by hydrogenating (hydrogenating) a polymer block composed of conjugated diene monomer units.

[0074] The conjugated diene monomer is not particularly limited as long as it is a monomer having two conjugated double bonds. Examples include 1,3-butadiene, 2-methyl-1,3-butadiene (isoprene), 2-methyl-1,3-pentadiene and analogous compounds thereof, and mixtures thereof. In this case, the addition structure of the diene may be either a 1,2-addition structure or another addition structure.

[0075] For example, in a polybutadiene block in which the conjugated diene monomer is 1,3-butadiene, the polybutadiene block may have either a 1,2-addition structure that gives an equivalent to a 1-butene repeating unit upon hydrogenation, or a 1,4-addition structure that gives an equivalent to an ethylene repeating unit upon hydrogenation. The acyclic aliphatic low-crystalline resin segment (A-c) in this embodiment is preferably, for example, an ethylene-butene copolymer obtained by hydrogenating an ethylene-butadiene copolymer.

[0076] A preferred embodiment of the block copolymer (A) that satisfies the relationship of the above formula (1) is one in which the amorphous resin segment (A-a) is a vinylcyclohexane-based polymer and the low-crystalline resin segment (Ac) is an ethylene-butene copolymer.

[0077] In the second aspect of the micro-channel chip according to the present embodiment, the melting point Tm(A1) of the low-crystalline resin segment (A1-c) contained in the block copolymer (A1) and the melting point Tm(A2) of the low-crystalline resin segment (A2-c) contained in the block copolymer (A2) satisfy the relationship of the following formula (2-1) with the glass transition temperature Tg(A1) of the block copolymer (A1) and the glass transition temperature Tg(A2) of the block copolymer (A2) (condition 2-iii): Formula (2-1): Tg(A1) - Tm(A1) ≧ 20°C and Tg(A2) - Tm(A2) ≧ 20°C.

[0078] As an embodiment that satisfies the conditions (2-i) to (2-iv) in the second embodiment, the amorphous resin segment (A1-a) and the amorphous resin segment (A2-a) of the block copolymer (A1) and the block copolymer (A2) are preferably vinylcyclohexane-based polymers, and the low-crystalline resin segment (A1-c) and the low-crystalline resin segment (A2-c) are preferably ethylene-butene copolymers.

[0079] The conditions (1-i) to (1-iii) and the conditions (2-i) to (2-iv) in this embodiment indicate that the block copolymer (A) or the block copolymers (A1) and (A2) have, in their molecules, segments that exhibit different thermal behavior.

[0080] Although the glass transition temperature Tg(A) and melting point Tm(A) are confirmed as temperatures showing peaks in each of the above-mentioned measurements, it is difficult to distinguish independently whether they are glass transition temperatures showing glass transition or melting points showing crystalline melting. However, if the temperatures showing peaks in each measurement are simply defined as the glass transition temperature Tg and melting point Tm, respectively, in a homopolymer or random copolymer, if it is a crystalline resin, it will generally exhibit a high melting point Tm and a low glass transition temperature Tg (Tm > Tg), and will not satisfy the relationship of the above formula (1) (condition 1-iii) or the above formula (2-1) (condition 2-iii) as in the block copolymer of this embodiment. Furthermore, in a homopolymer or random copolymer, if it is an amorphous resin, the glass transition temperature Tg and melting point Tm will have similar values, and similarly, will not satisfy the relationship of the above formula (1) (condition 1-iii) or the above formula (2-1) (condition 2-iii) as in the block copolymer of this embodiment.

[0081] As a result, if the block copolymer (A) or the block copolymers (A1) and (A2) in this embodiment do not satisfy the respective conditions required for them, the temperature range in which high bondability during production and good shape retention of the flow channel can be achieved at the same time is extremely narrow.

[0082] When the block copolymer (A) of this embodiment contains block copolymers (A1) and (A2), the content of block copolymer (A1) relative to the total of block copolymer (A1) and block copolymer (A2) may be 0% by mass or more and less than 100% by mass, for example, preferably 10 to 90% by mass, and more preferably 20 to 80% by mass. Here, the content may be 0% by mass or more and less than 100% by mass. Furthermore, from the viewpoint of widening the available temperature range, the content is preferably 10% by mass or more, more preferably 20% by mass or more, and preferably 90% by mass or less, and more preferably 80% by mass or less. As mentioned above, between block copolymer (A1) and block copolymer (A2), the block copolymer (A1) has a higher glass transition temperature.

[0083] The melt flow rate (MFR) of the block copolymer (A) in this embodiment is preferably 0.01 to 1000 g / 10 min. Here, from the viewpoint of moldability, the MFR is preferably 0.1 g / 10 min or more, more preferably 1 g / 10 min or more. Furthermore, from the viewpoint of strength, the MFR is preferably 1000 g / 10 min or less, more preferably 100 g / 10 min or less, and even more preferably 50 g / 10 min or less. Furthermore, depending on the purpose, the MFR may be 50 to 1000 g / 10 min or 100 to 500 g / 10 min.

[0084] In this specification, the melt flow rate (MFR) is a value measured in accordance with JIS K 7210:1999 under conditions of a temperature of 230°C and a load of 2.16 kg.

[0085] <Block Copolymer (B)> In one aspect of the micro-channel chip according to the present embodiment, the thermoplastic resin of at least one of the substrate having a channel groove and the cover plate bonded thereto contains a specific block copolymer (A) and a specific block copolymer (B). The block copolymer (A) and the block copolymer (B) satisfy the following conditions (3-i) to (3-v) (third aspect):

[0086] (3-i) The block copolymer (A) comprises an amorphous resin segment (A-a) having an alicyclic structure and an acyclic aliphatic low-crystalline resin segment (A-c). (3-ii) The glass transition temperature Tg(A) of the block copolymer (A) is in the range of 50 to 140°C. (3-iii) The glass transition temperature Tg(A) and the melting point Tm(A) of the block copolymer (A) satisfy the relationship of the following formula (3-1): Formula (3-1): Tg(A) - Tm(A) ≧ 20°C. (3-iv) The block copolymer (B) comprises an amorphous resin segment (B-a) having an aromatic hydrocarbon structure and an acyclic aliphatic low-crystalline resin segment (B-c). (3-v) The glass transition temperature Tg(A) of the block copolymer (A) and the glass transition temperature Tg(B) of the block copolymer (B) satisfy the relationship of the following formula (3-2). Formula (3-2): Tg(A)-Tg(B)≧10°C

[0087] Here, the above conditions (3-i) to (3-iii) regarding the block copolymer (A) are the same as the conditions (1-i) to (1-iii) described above in <Block copolymer (A) ((A1), (A2))>>, and preferred embodiments are also the same.

[0088] The block copolymer (A) may contain a block copolymer (A1) and a block copolymer (A2) (fourth embodiment). In this case, the block copolymer (A1) and the block copolymer (A2) are the same as the block copolymer (A1) and the block copolymer (A2), respectively, described above in <Block copolymer (A) ((A1), (A2))>>, and preferred embodiments are also the same.

[0089] The thermoplastic resin in this embodiment is a combination of the block copolymer (A) or the block copolymers (A1) and (A2) with a block copolymer (B) further comprising an amorphous resin segment (Ba) having an aromatic hydrocarbon structure and an acyclic aliphatic low-crystalline resin segment (Bc) (condition (3-iv)). This further widens the temperature range in which high bondability and good shape retention of the channel grooves can be achieved during the production of the microchannel chip.

[0090] In such a combination of block copolymer (A) and block copolymer (B), it is preferable that the glass transition temperature Tg(A) of block copolymer (A) and the glass transition temperature Tg(B) of block copolymer (B) satisfy the following formula (3-2) (condition (3-v)): Formula (3-2): Tg(A) - Tg(B) ≥ 10°C

[0091] When the block copolymer (A) is composed of a block copolymer (A1) and a block copolymer (A2), the glass transition temperature Tg(A2) of the block copolymer (A2) is lower than that of the block copolymer (A1), and the glass transition temperature Tg(B) of the block copolymer (B) preferably satisfies the following formula (4-3) (condition (4-vi)): Tg(A2) - Tg(B) ≥ 10°C.

[0092] The difference in glass transition temperature may be at least 10° C., and is preferably at least 15° C. The upper limit of the difference is not particularly limited, but is, for example, 100° C. or less.

[0093] When the block copolymer (B) contains a plurality of amorphous resin segments, the block copolymer (B) may have a plurality of glass transition temperatures. In such a case, it is preferable that the highest peak temperature at which a peak of loss modulus G" is observed in solid state viscoelasticity measurement (DMA; Dynamic Mechanical Analysis) is defined as Tg(B), and that this value satisfies the above formula (3-2) or (4-3). However, this does not exclude cases where other glass transition temperatures exist outside the range.

[0094] Examples of the amorphous resin segment (Ba) having an aromatic hydrocarbon structure in this embodiment include a segment having an aromatic vinyl monomer as a constituent unit. Among these, a segment having an aromatic vinyl monomer as a constituent unit is preferred.

[0095] The aromatic vinyl monomer is more preferably styrene or a styrene derivative such as α-methylstyrene.

[0096] Low-Crystalline Resin Segment (B-c) In this embodiment, the low-crystalline resin segment (B-c) is an acyclic aliphatic low-crystalline resin segment. The melting point Tm and glass transition temperature Tg(B) of the low-crystalline resin segment (B-c) are not particularly limited.

[0097] In the block copolymer (B) of this embodiment, the glass transition temperature Tg(B) and the melting point Tm(B) preferably satisfy the relationship Tg(B) > Tm(B), and more preferably satisfy the relationship Tg(B) - Tm(B) ≥ 20°C.

[0098] In the present embodiment, the acyclic aliphatic of the acyclic aliphatic low-crystalline resin segment (B-c) may be either linear or branched. However, from the viewpoint of the productivity of the block copolymer (B), it is preferably a block obtained by hydrogenating a polymer block composed of conjugated diene monomer units.

[0099] The conjugated diene monomer is not particularly limited as long as it is a monomer having two conjugated double bonds, and examples thereof include 1,3-butadiene, 2-methyl-1,3-butadiene (isoprene), 2-methyl-1,3-pentadiene and analogous compounds thereof, and mixtures thereof, with 1,3-butadiene and / or isoprene being preferred, and butadiene being more preferred.

[0100] In the present embodiment, one aspect of the block copolymer (B) containing the amorphous resin segment (Ba) having an aromatic hydrocarbon structure and the acyclic aliphatic low-crystalline resin segment (B-c) is preferably a block copolymer containing a polymer block containing an aromatic vinyl monomer unit and a polymer block containing a conjugated diene monomer unit, and further preferably a styrene-based block copolymer in which the conjugated diene monomer unit is hydrogenated.

[0101] More specifically, styrene-butadiene copolymer rubber and styrene-isoprene copolymer rubber are particularly preferred. As the hydrogenated styrene-based block copolymer, styrene-butadiene copolymer rubber and styrene-isoprene copolymer rubber in which the polybutadiene block unit or the polyisoprene block unit is hydrogenated are particularly preferred.

[0102] In this embodiment, the content of block copolymer (B) relative to the total of block copolymer (A) and block copolymer (B) is preferably 0 to 80% by mass, more preferably 5 to 60% by mass. When block copolymer (B) is contained, the content is preferably 5% by mass or more from the viewpoint of realizing a wider temperature range in which high bondability and good shape retention of the channel grooves can be achieved simultaneously during the production of the microchannel chip. Furthermore, from the viewpoint of good moldability and surface smoothness, the content is preferably 80% by mass or less, more preferably 60% by mass or less.

[0103] When the block copolymer (A) contains the block copolymers (A1) and (A2), the content of the block copolymer (B) relative to the total content of the block copolymer (A1), the block copolymer (A2), and the block copolymer (B) preferably falls within the above-mentioned range.

[0104] <Other Components> The thermoplastic resin used in the micro-channel chip according to this embodiment may further contain other components as constituents, to the extent that the object of the present invention is not impaired. Examples of other components include additives such as stabilizers, other resin components, elastomer components, inorganic fillers, etc.

[0105] When the thermoplastic resin contains other components, the total content of the other components may be, for example, more than 0 mass % and not more than 30 mass %, or may be 1 to 25 mass %.

[0106] <Production Method> The method for producing the thermoplastic resin used in the micro-channel chip according to this embodiment is not particularly limited. For example, the components of a block copolymer or the like may be simply blended, or the resin may be produced using various melt-kneading devices used in the production of general thermoplastic resins. Among these, production using a melt-kneading device is preferred.

[0107] Examples of the melt-kneading device include a single-screw extruder, a twin-screw extruder, a Banbury mixer, a roll, a Brabender Plastograph, and a Kneader Brabender.

[0108] The melt-kneading conditions may be appropriately set. For example, the temperature during melt-kneading may be 160 to 320°C, or 180 to 300°C.

[0109] <Substrate with Flow Channel and Cover Plate> The microchannel chip according to this embodiment includes at least two plates: a substrate with flow channel and a cover plate. The cover plate is bonded to the substrate so as to cover the flow channel. By performing the bonding by thermal fusion, adverse effects on the contents due to adhesives and the like can be prevented. Furthermore, since bonding can be performed at a relatively low temperature, there is little effect on the contents, the plate has excellent transparency, and there is little autofluorescence.

[0110] In the microchannel chip according to this embodiment, the thermoplastic resin of at least one of the substrate having a channel groove and the cover plate may be a thermoplastic resin that satisfies the above-mentioned conditions. From the viewpoint of suppressing warping during heat fusion and obtaining smoothness of the channel, it is preferable that both the substrate and the cover plate are made of the thermoplastic resin according to this embodiment. However, this does not exclude the case where only one of the substrate or the cover plate is made of a thermoplastic resin. When the substrate having a channel groove or the cover plate is made of a material other than a thermoplastic resin, for example, an inorganic material such as glass can be used.

[0111] That is, the substrate having the flow channel according to this embodiment may have the following configurations.

[0112] Aspect 1' A substrate having a flow channel, for use in a microchannel chip, comprising a thermoplastic resin, the thermoplastic resin containing, as a constituent, a block copolymer (A)' that satisfies the following conditions (1-i)' to (1-iii)'. (1-i) The block copolymer (A)' contains an amorphous resin segment (A-a)' having an alicyclic structure, and an acyclic aliphatic low-crystalline resin segment (A-c). (1-ii) The glass transition temperature Tg(A)' of the block copolymer (A)' is in the range of 50 to 140°C. (1-iii) The glass transition temperature Tg(A)' and the melting point Tm(A)' of the block copolymer (A)' satisfy the relationship of the following formula (1)'. Formula (1)': Tg(A)' - Tm(A)' ≧ 20°C

[0113] Aspect 2': A substrate having a flow channel, for use in a microchannel chip, comprising a thermoplastic resin, the thermoplastic resin containing, as constituent components, a block copolymer (A1)' and a block copolymer (A2)' that satisfy the following conditions (2-i)' to (2-iv): (2-i) The block copolymer (A1)' contains an amorphous resin segment (A1-a)' having an alicyclic structure and an acyclic aliphatic low-crystalline resin segment (A1-c)', and the block copolymer (A2)' contains an amorphous resin segment (A2-a)' having an alicyclic structure and an acyclic aliphatic low-crystalline resin segment (A2-c)'. (2-ii) The glass transition temperature Tg(A1)' of the block copolymer (A1)' and the glass transition temperature Tg(A2)' of the block copolymer (A2)' are each in the range of 50 to 140°C. (2-iii) The glass transition temperature Tg(A1)' and melting point Tm(A1)' of the block copolymer (A1)', and the glass transition temperature Tg(A2)' and melting point Tm(A2)' of the block copolymer (A2)' satisfy the relationship of the following formula (2-1)'. Formula (2-1)': Tg(A1)'-Tm(A1)'≧20°C, and Tg(A2)'-Tm(A2)'≧20°C. (2-iv) The glass transition temperature Tg(A1)' of the block copolymer (A1)' and the glass transition temperature Tg(A2)' of the block copolymer (A2)' satisfy the relationship of the following formula (2-2)'. Formula (2-2)': Tg(A1)'-Tg(A2)'≧5°C.

[0114] Aspect 3' A substrate having a flow channel, for use in a microchannel chip, comprising a thermoplastic resin, the thermoplastic resin containing, as constituent components, a block copolymer (A)' and a block copolymer (B)' that satisfy the following conditions (3-i)' to (3-v)': (3-i) The block copolymer (A)' contains an amorphous resin segment (A-a)' having an alicyclic structure, and an acyclic aliphatic low-crystalline resin segment (A-c)'. (3-ii) The block copolymer (A)' has a glass transition temperature Tg(A)' in the range of 50 to 140°C. (3-iii) The glass transition temperature Tg(A)' and the melting point Tm(A)' of the block copolymer (A)' satisfy the relationship of the following formula (3-1)': Formula (3-1)': Tg(A)'-Tm(A)'≧20°C. (3-iv)' The block copolymer (B)' comprises an amorphous resin segment (Ba)' having an aromatic hydrocarbon structure, and an acyclic aliphatic low-crystalline resin segment (B-c)'. (3-v)' The glass transition temperature Tg(A)' of the block copolymer (A)' and the glass transition temperature Tg(B)' of the block copolymer (B)' satisfy the relationship of the following formula (3-2)'. Formula (3-2)': Tg(A)'-Tg(B)'≧10°C.

[0115] Aspect 4' A substrate having a flow channel for use in a microchannel chip, the substrate being made of a thermoplastic resin, the thermoplastic resin containing, as constituent components, a block copolymer (A1)', a block copolymer (A2)', and a block copolymer (B)' that satisfy the following conditions (4-i)' to (4-vi): (4-i) The block copolymer (A1)' contains an amorphous resin segment (A1-a)' having an alicyclic structure and an acyclic aliphatic low-crystalline resin segment (A1-c)', and the block copolymer (A2)' contains an amorphous resin segment (A2-a)' having an alicyclic structure and an acyclic aliphatic low-crystalline resin segment (A2-c)'. (4-ii) The glass transition temperature Tg(A1)' of the block copolymer (A1)' and the glass transition temperature Tg(A2)' of the block copolymer (A2)' are each in the range of 50 to 140°C. (4-iii) The glass transition temperature Tg(A1)' and melting point Tm(A1)' of the block copolymer (A1)', and the glass transition temperature Tg(A2)' and melting point Tm(A2)' of the block copolymer (A2)' satisfy the relationship of the following formula (4-1)': Formula (4-1)': Tg(A1)'-Tm(A1)'≧20°C, and Tg(A2)'-Tm(A2)'≧20°C. (4-iv) The glass transition temperature Tg(A1)' of the block copolymer (A1)' and the glass transition temperature Tg(A2)' of the block copolymer (A2)' satisfy the relationship of the following formula (4-2)'. Formula (4-2)': Tg(A1)'-Tg(A2)'≧5°C. (4-v)' The block copolymer (B)' comprises an amorphous resin segment (Ba)' having an aromatic hydrocarbon structure, and an acyclic aliphatic low-crystalline resin segment (B-c)'. (4-vi)' The glass transition temperature Tg(A2)' of the block copolymer (A2)' and the glass transition temperature Tg(B)' of the block copolymer (B)' satisfy the relationship of the following formula (4-3)'. Formula (4-3)': Tg(A2)'-Tg(B)'≧10°C.

[0116] Here, the conditions (1-i)' to (1-iii)', block copolymer (A)', amorphous resin segment (A-a)' having an alicyclic structure, acyclic aliphatic low-crystalline resin segment (Ac)', glass transition temperature Tg(A)', melting point Tm(A)', and formula (1)' in the above-mentioned Aspect 1' are the same as the conditions (1-i) to (1-iii), block copolymer (A), amorphous resin segment (A-a) having an alicyclic structure, acyclic aliphatic low-crystalline resin segment (Ac), glass transition temperature Tg(A), melting point Tm(A), and formula (1) for the thermoplastic resin described above, respectively, and preferred aspects are also the same.

[0117] In addition, the conditions (2-i)' to (2-iv)', the block copolymer (A1)', the block copolymer (A2)', the amorphous resin segment (A1-a)' having an alicyclic structure, the acyclic aliphatic low-crystalline resin segment (A1-c)', the amorphous resin segment (A2-a)' having an alicyclic structure, the acyclic aliphatic low-crystalline resin segment (A2-c)', the glass transition temperature Tg(A1)', the glass transition temperature Tg(A2)', the melting point Tm(A1)', the melting point Tm(A2)', the formula (2-1)', and the formula (2-2)' in the above aspect 2' are respectively defined as follows: The conditions (2-i) to (2-iv) for the thermoplastic resin described above are the same as those for the block copolymer (A1), the block copolymer (A2), the amorphous resin segment (A1-a) having an alicyclic structure, the acyclic aliphatic low-crystalline resin segment (A1-c), the amorphous resin segment (A2-a) having an alicyclic structure, the acyclic aliphatic low-crystalline resin segment (A2-c), the glass transition temperature Tg(A1), the glass transition temperature Tg(A2), the melting point Tm(A1), the melting point Tm(A2), the formula (2-1), and the formula (2-2), and preferred aspects are also the same.

[0118] In addition, the conditions (3-i)' to (3-v)', the block copolymer (A)', the block copolymer (B)', the amorphous resin segment (A-a)' having an alicyclic structure, the acyclic aliphatic low-crystalline resin segment (A-c)', the glass transition temperature Tg(A)', the melting point Tm(A)', the amorphous resin segment (B-a)' having an aromatic hydrocarbon structure, the acyclic aliphatic low-crystalline resin segment (B-c)', the glass transition temperature Tg(B)', the formula (3-1)', and the formula (3-2)' in the above aspect 3' are respectively defined as follows. The conditions (3-i) to (3-v) for the thermoplastic resin described above are the same as those for the block copolymer (A), the block copolymer (B), the amorphous resin segment (A-a) having an alicyclic structure, the acyclic aliphatic low-crystalline resin segment (A-c), the glass transition temperature Tg(A), the melting point Tm(A), the amorphous resin segment (B-a) having an aromatic hydrocarbon structure, the acyclic aliphatic low-crystalline resin segment (B-c), the glass transition temperature Tg(B), formula (3-1), and formula (3-2), and preferred aspects are also the same.

[0119] In addition, the conditions (4-i)' to (4-vi)', the block copolymer (A1)', the block copolymer (A2)', the block copolymer (B)', the amorphous resin segment (A1-a)' having an alicyclic structure, the non-cyclic aliphatic low-crystalline resin segment (A1-c)', the amorphous resin segment (A2-a)' having an alicyclic structure, the non-cyclic aliphatic low-crystalline resin segment (A2-c)', the glass transition temperature Tg(A1)', the glass transition temperature Tg(A2)', the melting point Tm(A1)', the melting point Tm(A2)', the amorphous resin segment (B-a)' having an aromatic hydrocarbon structure, the non-cyclic aliphatic low-crystalline resin segment (B-c)', the glass transition temperature Tg(B)', the formula (4-1)', the formula (4-2)', and the formula (4-3)' in the above-mentioned aspect 4' respectively. The conditions for the thermoplastic resin described above (4-i) to (4-vi), block copolymer (A1), block copolymer (A2), block copolymer (B), amorphous resin segment having an alicyclic structure (A1-a), acyclic aliphatic low-crystalline resin segment (A1-c), amorphous resin segment having an alicyclic structure (A2-a), acyclic aliphatic low-crystalline resin segment (A2-c), glass transition temperature Tg (A1), glass transition temperature Tg (A2), melting point Tm (A1), melting point Tm (A2), amorphous resin segment having an aromatic hydrocarbon structure (B-a), acyclic aliphatic low-crystalline resin segment (B-c), glass transition temperature Tg (B), formula (4-1), formula (4-2), and formula (4-3) are the same, and preferred embodiments are also the same.

[0120] The cover plate according to this embodiment may have the following configuration.

[0121] Aspect 1″ is a cover plate for use in a micro-channel chip, the cover plate being bonded to a substrate having a channel groove so as to cover the substrate, the cover plate being made of a thermoplastic resin, the thermoplastic resin containing, as a constituent, a block copolymer (A)″ that satisfies the following conditions (1-i)″ to (1-iii)″. (1-i)″ The block copolymer (A)″ contains an amorphous resin segment (A-a)″ having an alicyclic structure, and an acyclic aliphatic low-crystalline resin segment (A-c)″. (1-ii)″ The glass transition temperature Tg(A)″ of the block copolymer (A)″ is in the range of 50 to 140°C. (1-iii)″ The glass transition temperature Tg(A)″ and the melting point Tm(A)″ of the block copolymer (A)″ satisfy the relationship of the following formula (1)″. Formula (1)″: Tg(A)″-Tm(A)″≧20°C

[0122] Aspect 2″ is a cover plate for use in a micro-channel chip, the cover plate being bonded to a substrate having a channel groove so as to cover the substrate, the cover plate being made of a thermoplastic resin, the thermoplastic resin containing, as constituent components, a block copolymer (A1)″ and a block copolymer (A2)″ that satisfy the following conditions (2-i)″ to (2-iv)′″: (2-i)″ the block copolymer (A1)″ comprises an amorphous resin segment (A1-a)″ having an alicyclic structure and an acyclic aliphatic low-crystalline resin segment (A1-c)″, and the block copolymer (A2)″ comprises an amorphous resin segment (A2-a)″ having an alicyclic structure and an acyclic aliphatic low-crystalline resin segment (A2-c)″. (2-ii) The glass transition temperature Tg(A1)'' of the block copolymer (A1)'' and the glass transition temperature Tg(A2)'' of the block copolymer (A2)'' are each in the range of 50 to 140°C. (2-iii) The glass transition temperature Tg(A1)'' and the melting point Tm(A1)'' of the block copolymer (A1)'' and the glass transition temperature Tg(A2)'' and the melting point Tm(A2)'' of the block copolymer (A2)'' satisfy the relationship of the following formula (2-1)''. Formula (2-1)": Tg(A1)"-Tm(A1)"≧20°C, and Tg(A2)"-Tm(A2)"≧20°C. (2-iv)" The glass transition temperature Tg(A1)" of the block copolymer (A1)" and the glass transition temperature Tg(A2)" of the block copolymer (A2)" satisfy the relationship of the following formula (2-2)". Formula (2-2)": Tg(A1)"-Tg(A2)"≧5°C.

[0123] Aspect 3'' A cover plate for use in a micro-channel chip, the cover plate being bonded to a substrate having a channel groove so as to cover the substrate, the cover plate being made of a thermoplastic resin, the thermoplastic resin containing, as constituent components, a block copolymer (A)'' and a block copolymer (B)'' that satisfy the following conditions (3-i)'' to (3-v)''. (3-i)'' The block copolymer (A)'' contains an amorphous resin segment (A-a)'' having an alicyclic structure, and an acyclic aliphatic low-crystalline resin segment (A-c)''. (3-ii)'' The block copolymer (A)'' has a glass transition temperature Tg(A)'' in the range of 50 to 140°C. (3-iii)'' The glass transition temperature Tg(A)'' and the melting point Tm(A)'' of the block copolymer (A)'' satisfy the relationship of the following formula (3-1)''. Formula (3-1)': Tg(A)'-Tm(A)'≧20°C. (3-iv)'The block copolymer (B)' comprises an amorphous resin segment (B-a)' having an aromatic hydrocarbon structure and an acyclic aliphatic low-crystalline resin segment (B-c)'. (3-v)'The glass transition temperature Tg(A)' of the block copolymer (A)' and the glass transition temperature Tg(B)' of the block copolymer (B)' satisfy the relationship of the following formula (3-2)'. Formula (3-2)': Tg(A)'-Tg(B)'≧10°C.

[0124] Aspect 4'' A cover plate for use in a micro-channel chip, the cover plate being bonded to a substrate having a channel groove so as to cover the substrate, the cover plate being made of a thermoplastic resin, the thermoplastic resin containing, as constituent components, a block copolymer (A1)'', a block copolymer (A2)'', and a block copolymer (B)'', which satisfy the following conditions (4-i)'' to (4-vi)'': (4-i)'' The block copolymer (A1)'' contains an amorphous resin segment (A1-a)'' having an alicyclic structure and an acyclic aliphatic low-crystalline resin segment (A1-c)'', and the block copolymer (A2)'' contains an amorphous resin segment (A2-a)'' having an alicyclic structure and an acyclic aliphatic low-crystalline resin segment (A2-c)''. (4-ii) The glass transition temperature Tg(A1)'' of the block copolymer (A1)'' and the glass transition temperature Tg(A2)'' of the block copolymer (A2)'' are each in the range of 50 to 140°C. (4-iii) The glass transition temperature Tg(A1)'' and the melting point Tm(A1)'' of the block copolymer (A1)'' and the glass transition temperature Tg(A2)'' and the melting point Tm(A2)'' of the block copolymer (A2)'' satisfy the relationship of the following formula (4-1)''. Formula (4-1)": Tg(A1)"-Tm(A1)"≧20°C, and Tg(A2)"-Tm(A2)"≧20°C. (4-iv)" The glass transition temperature Tg(A1)" of the block copolymer (A1)" and the glass transition temperature Tg(A2)" of the block copolymer (A2)" satisfy the relationship of the following formula (4-2)". Formula (4-2)": Tg(A1)"-Tg(A2)"≧5°C. (4-v)" The block copolymer (B)" comprises an amorphous resin segment (Ba)" having an aromatic hydrocarbon structure, and an acyclic aliphatic low-crystalline resin segment (B-c)". (4-vi) The glass transition temperature Tg(A2)'' of the block copolymer (A2)'' and the glass transition temperature Tg(B)'' of the block copolymer (B)'' satisfy the relationship of the following formula (4-3)''. Formula (4-3)'': Tg(A2)''-Tg(B)''≧10°C

[0125] Here, the conditions (1-i)'' to (1-iii)'', block copolymer (A)'', amorphous resin segment (A-a)'' having an alicyclic structure, acyclic aliphatic low-crystalline resin segment (Ac)'', glass transition temperature Tg(A)'', melting point Tm(A)'', and formula (1)'' in the above-mentioned Aspect 1'' are the same as the conditions (1-i) to (1-iii), block copolymer (A), amorphous resin segment (A-a) having an alicyclic structure, acyclic aliphatic low-crystalline resin segment (Ac), glass transition temperature Tg(A), melting point Tm(A), and formula (1) for the thermoplastic resin described above, respectively, and preferred aspects are also the same.

[0126] Furthermore, the conditions (2-i)'' to (2-iv)'' in Aspect 2'' above, the block copolymer (A1)'', the block copolymer (A2)'', the amorphous resin segment (A1-a)'' having an alicyclic structure, the acyclic aliphatic low-crystalline resin segment (A1-c)'', the amorphous resin segment (A2-a)'' having an alicyclic structure, the acyclic aliphatic low-crystalline resin segment (A2-c)'', the glass transition temperature Tg(A1)'', the glass transition temperature Tg(A2)'', the melting point Tm(A1)'', the melting point Tm(A2)'', the formula (2-1)'', and the formula (2-2)' ' are the same as the conditions (2-i) to (2-iv) for the thermoplastic resin described above, the block copolymer (A1), the block copolymer (A2), the amorphous resin segment (A1-a) having an alicyclic structure, the acyclic aliphatic low-crystalline resin segment (A1-c), the amorphous resin segment (A2-a) having an alicyclic structure, the acyclic aliphatic low-crystalline resin segment (A2-c), the glass transition temperature Tg(A1), the glass transition temperature Tg(A2), the melting point Tm(A1), the melting point Tm(A2), the formula (2-1), and the formula (2-2), and preferred aspects are also the same.

[0127] Furthermore, the conditions (3-i)'' to (3-v)'' in Aspect 3'' above, the block copolymer (A)'', the block copolymer (B)'', the amorphous resin segment (A-a)'' having an alicyclic structure, the acyclic aliphatic low-crystalline resin segment (A-c)'', the glass transition temperature Tg(A)'', the melting point Tm(A)'', the amorphous resin segment (B-a)'' having an aromatic hydrocarbon structure, the acyclic aliphatic low-crystalline resin segment (B-c)'', the glass transition temperature Tg(B)'', Formula (3-1)'', and Formula (3-2)'' are the same as the conditions (3-i) to (3-v) for the thermoplastic resin described above, the block copolymer (A), the block copolymer (B), the amorphous resin segment (A-a) having an alicyclic structure, the acyclic aliphatic low-crystalline resin segment (A-c), the glass transition temperature Tg(A), the melting point Tm(A), the amorphous resin segment (B-a) having an aromatic hydrocarbon structure, the acyclic aliphatic low-crystalline resin segment (B-c), the glass transition temperature Tg(B), formula (3-1), and formula (3-2), and preferred aspects are also the same.

[0128] Furthermore, the conditions (4-i)'' to (4-vi)'' in Aspect 4'' above, the block copolymer (A1)'', the block copolymer (A2), the block copolymer (B), the amorphous resin segment (A1-a)'' having an alicyclic structure, the acyclic aliphatic low-crystalline resin segment (A1-c), the amorphous resin segment (A2-a)'' having an alicyclic structure, the acyclic aliphatic low-crystalline resin segment (A2-c), the glass transition temperature Tg(A1), the glass transition temperature Tg(A2), the melting point Tm(A1), the melting point Tm(A2), the amorphous resin segment (B-a)'' having an aromatic hydrocarbon structure, the acyclic aliphatic low-crystalline resin segment (B-c), the glass transition temperature Tg(B), the formula (4-1), the formula (4-2), and the formula ( 4-3)'' are the same as the conditions (4-i) to (4-vi) for the thermoplastic resin described above, the block copolymer (A1), the block copolymer (A2), the block copolymer (B), the amorphous resin segment having an alicyclic structure (A1-a), the acyclic aliphatic low-crystalline resin segment (A1-c), the amorphous resin segment having an alicyclic structure (A2-a), the acyclic aliphatic low-crystalline resin segment (A2-c), the glass transition temperature Tg (A1), the glass transition temperature Tg (A2), the melting point Tm (A1), the melting point Tm (A2), the amorphous resin segment having an aromatic hydrocarbon structure (B-a), the acyclic aliphatic low-crystalline resin segment (B-c), the glass transition temperature Tg (B), the formula (4-1), the formula (4-2), and the formula (4-3), and preferred aspects are also the same.

[0129] When the substrate and the cover plate are each made of the thermoplastic resin in this embodiment, the thermoplastic resin constituting the substrate and the thermoplastic resin constituting the cover plate may be the same or different, but from the viewpoint of suppressing warping during heat fusion and obtaining smoothness of the flow path, it is preferable that they are the same.

[0130] The shape of the flow channel can be a wide variety of known microchannels. Therefore, the microchannel chip according to this embodiment can be widely applied to, for example, microarrays, micro-TAS (Micro-Total Analysis Systems), microreactors, etc. Note that the microchannel chip in this specification refers to a microchip that has minute recesses, minute grooves, and flow channels of several μm to several tens of μm in size, and that enables chemical reactions utilizing phenomena within a microspace, mixing, reaction, separation, and the like for material production.

[0131] Furthermore, the microchannel chip according to this embodiment can be applied to a microchip body having two or more resin plates, including the substrate and cover plate, tightly bonded to each other and having two-dimensional or three-dimensional microchannels or nanochannels.

[0132] The flow channel grooves can be formed in the substrate by various known methods, such as a method of forming the flow channel directly in a mold or a roll and transferring it, or a method of etching with a laser or the like.

[0133] The thickness of the substrate having the channel groove is not particularly limited as long as it can achieve the intended use of the microchannel, but for example, when the channel formed in a mold is transferred by injection molding, it is preferably about 0.5 to 4 mm from the viewpoint of fluidity and transferability. The thickness of the cover plate is also not particularly limited as long as it can achieve the intended use of the microchannel, but for example, it is preferably about 0.03 to 4 mm.

[0134] The base plate and cover plate having the flow channel grooves can be formed by a wide range of known methods such as injection molding, extrusion molding, press molding, etc.

[0135] The substrate having the flow channel grooves and the cover plate can be bonded by heat fusion using various known heating methods, including a method of directly contacting a heat source such as a heat press or a heated compression roll, a method using heat transfer or radiation such as an electric oven, a method of converting vibration energy into heat such as ultrasonic waves, and a method of heating using electromagnetic waves or a laser.

[0136] The conditions for joining the substrate having the flow channel groove and the cover plate by heat fusion are not particularly limited, but for example, the substrate and cover plate may be pressed in a heated state for several seconds to several tens of minutes. The pressing pressure may be within a range that ensures firm adhesion between the substrate and the cover plate and does not cause excessive deformation of the flow channel, for example, 0.1 to 100 kfg / cm. ２ The range can be:

[0137] From the viewpoint of productivity, the temperature range at which heat sealing is possible is preferably 5° C. or higher, more preferably 10° C. or higher, and the wider the range, the better. Furthermore, from the viewpoint of the effect on the contents and maintaining the shape of the flow channel, the temperature at which heat sealing is possible is preferably 120° C. or lower, more preferably 100° C. or lower. Furthermore, from the viewpoint of heat resistance during use, the temperature is preferably 40° C. or higher, more preferably 60° C. or higher.

[0138] The microchannel chip according to this embodiment is often required to be able to observe the interior thereof, and therefore preferably has high transparency. Therefore, the haze value of the microchannel chip is preferably 10% or less, more preferably 5% or less, and the lower the better, but may be, for example, 0.05% or more. In this specification, the haze value is a value measured in accordance with ISO 14782.

[0139] The present invention will be described in more detail below using examples, but the present invention is not limited to the following examples as long as it does not deviate from the gist of the invention. The values ​​of various production conditions and evaluation results in the following examples represent preferred upper or lower limit values ​​in the embodiments of the present invention, and preferred ranges may be defined by combining the above-mentioned upper or lower limit values ​​with the values ​​in the following examples, or by combining the values ​​in the following examples together.

[0140] <<Raw Materials>> The raw materials used in the examples and comparative examples are shown below.

[0141] <Block Copolymer (A)> Three types of block copolymers (A-1) to (A-3) were used, each having a polyvinylcyclohexane segment, which is a hydrogenated product of a polymer block composed of aromatic vinyl monomer units, as the amorphous resin segment (A-a) having an alicyclic structure, and an ethylene-butene copolymer segment, which is a hydrogenated product of a polymer block composed of butadiene monomer units, as the acyclic aliphatic low-crystalline resin segment (A-c). The physical properties of block copolymers (A-1) to (A-3) are shown in Table 1.

[0142] <Block Copolymer (B)> Two types of block copolymers, (B-1) and (B-2), were used, each having a polystyrene segment as the amorphous resin segment (B-a) having an aromatic hydrocarbon structure, and an ethylene-butene copolymer segment, which is a hydrogenated product of a polymer block composed of butadiene monomer units, as the acyclic aliphatic low-crystalline resin segment (B-c). The physical properties of block copolymer (B-1) and block copolymer (B-2) are shown in Table 2.

[0143] <Physical Properties of Raw Materials> <Melt Flow Rate (MFR)> The MFR of each block copolymer was measured in accordance with JIS K 7210 (1999) under the following conditions. The results are shown in Tables 1 and 2. Apparatus: Melt Indexer manufactured by Toyo Seiki Seisakusho, Ltd. Temperature: 230°C Orifice diameter: 2 mm Load: 2.16 kg

[0144] <Glass Transition Temperature Tg> The peak temperature of the loss modulus G'' in solid viscoelasticity measurement (DMA) was measured under the following conditions, and the glass transition temperature Tg was determined. The results are shown in Tables 1 and 2. Measurement mode: torsion Heating rate: 2°C / min Frequency: 1 Hz Strain: 0.5%

[0145] <Melting point Tm> Using a differential scanning calorimeter (DSC), a sample was once heated to 200°C and melted, cooled to -60°C at a cooling rate of 10°C / min, and then heated again at 10°C / min, and the endothermic peak temperature was measured, and the peak temperature of the maximum endothermic peak was taken as the melting point Tm. The results are shown in Tables 1 and 2.

[0146] <Hydrogenation Level> For block copolymers (A-1) to (A-3), the hydrogenation levels of the aromatic ring moieties of the aromatic vinyl polymers were determined by proton NMR measurement under the following conditions: Apparatus: JASCO Corporation "400YH Spectrometer" Solvent: deuterated chloroform Concentration: 0.045 g / 1.0 mL Measurement: １ H-NMR Resonance frequency: 400 MHz Number of accumulations: 8 Measurement temperature: 18.5°C

[0147] The hydrogenation level of the hydrogenated aromatic vinyl polymer block unit of the cyclic polyolefin was determined from the reduction rate of the integrated value between 6.8 and 7.5 ppm in the obtained NMR spectrum. The hydrogenation level of the hydrogenated conjugated diene polymer block unit of the cyclic polyolefin was determined from the reduction rate of the integrated value between 5.7 and 6.4 ppm in the obtained NMR spectrum. The results are shown in Table 1.

[0148]

[0149]

[0150] Examples and Comparative Examples Resins The above block copolymers were blended in the ratios (% by mass) shown in Table 3, and the blends were melt-kneaded at 260°C using a twin-screw extruder to obtain thermoplastic resins C1 to C8.

[0151] Resin D1 used was an amorphous polyolefin (manufactured by Zeon Corporation, COP). The glass transition temperature Tg was 102°C, and no melting point Tm was observed. However, a slight endothermic peak was confirmed at 106°C in DSC measurement. Therefore, the melting point Tm is shown in parentheses in Table 4. Resin D2 used was an amorphous polyolefin (manufactured by Zeon Corporation, COP). The glass transition temperature Tg was 136°C, and no melting point Tm was observed. However, a slight endothermic peak was confirmed at 143°C in DSC measurement. Therefore, the melting point Tm is shown in parentheses in Table 4. Resin E1 used was a crystalline ethylene-butene copolymer (manufactured by Prime Polymer Co., Ltd., Toughmer). The glass transition temperature Tg was -30°C, and the melting point Tm was 80°C.

[0152]

[0153]

[0154] Examples 1-1 to 1-8, Comparative Examples 1-1 to 1-3: A substrate and a cover plate with flow channel grooves were prepared using the resins in the combinations shown in Table 5, and these were bonded by thermal fusion to obtain a microchannel chip. Eleven temperatures in 5°C increments within the range of 80 to 130°C were used for bonding, and the temperature range in which high bonding and good shape retention of the flow channel grooves could be achieved was evaluated.

[0155] Substrates with flow channel grooves were fabricated using the following procedure. A mold with flow channel sections was attached to an injection molding machine (SE18D, manufactured by Sumitomo Heavy Industries, Ltd.). The mold had a plate-shaped cavity surface measuring 2 mm thick, 40 mm wide, and 80 mm long, with three patterns of flow channel sections with widths of 0.1 mm, 0.3 mm, and 0.5 mm and heights of 0.04 mm. Each resin was then injection molded at a molding temperature of 260°C and a mold temperature of 80°C to fabricate substrates with micro-flow channel grooves.

[0156] The cover plates were fabricated using the following procedure: A mold with a plate-shaped cavity measuring 1 mm thick, 40 mm wide, and 80 mm long was attached to an injection molding machine (SE18D, manufactured by Sumitomo Heavy Industries, Ltd.). Each resin was then injection molded at a molding temperature of 260°C and a mold temperature of 80°C to fabricate the cover plates.

[0157] The substrate and cover plate obtained above were bonded by heat fusion according to the following procedure: The substrate and cover plate were stacked so as to cover the flow channel of the substrate, and a heat press was used to apply a surface pressure of 8 kfg / cm ２ The heat fusion was performed for 3 minutes at a temperature of 80 to 130°C in 5°C increments, as described above, to obtain 11 types of microchannel chips for each example and comparative example.

[0158] <Evaluation> Transparency The transparency of the obtained microchannel chip was evaluated by the haze value measured in accordance with ISO 14782 using a haze meter (NDH2000, manufactured by Nippon Denshoku Industries Co., Ltd.). The results are shown in Table 5. Note that, since there was little change in the haze value due to differences in the temperature during bonding, Table 5 lists the haze value when bonding was performed at 100°C.

[0159] Shape retention The appearance of the channel grooves of the obtained microchannel chip was evaluated visually. The results are shown in Table 5, and the evaluation criteria were as follows: ◎: No defects anywhere in the channel. ○: Part of the channel is missing. △: Shallow or wide parts of the channel are crushed. ×: The channel is crushed throughout. XX: The channel has completely disappeared.

[0160] - Bonding The obtained microchannel chip was manually peeled from the joining point between the base plate and the cover plate, and the degree of bonding was evaluated. The results are shown in Table 5, and the evaluation criteria were as follows: ◎: Cannot be peeled at all even with force. ○: Peeling occurs slightly, but not completely. △: Peeling is possible, but strong force is required. ×: Peeled easily with weak force. -: Not bonded at all.

[0161] When the evaluation results for shape retention and bondability of the microchannel chip according to this embodiment are both ◎, ○, or △, it can be judged that both high bondability during manufacturing and good shape retention of the channel grooves are achieved. The wider the temperature range that yields such evaluation results, the better, and the higher the productivity can be evaluated. Furthermore, the lower the lower limit of the temperature range, the better. Note that ◎ or ○ is more preferable for all of the above evaluation results, and ◎ is even more preferable for both.

[0162] Furthermore, the temperature range in which the evaluation results for both items are ◎, ○, or △ is a suitable bonding temperature range for manufacturing such a microchannel chip, the temperature range in which both items are ◎ or ○ is a more suitable bonding temperature range, and the temperature range in which both items are ◎ is an even more suitable bonding temperature range.

[0163]

[0164] Examples 2-1 and 2-2: Using the resins in the combinations shown in Table 6, a substrate and a cover plate with flow channels were prepared, and these were then bonded by heat fusion to obtain a microchannel chip. Seven temperatures in 5°C increments within the range of 100 to 130°C were used during bonding, and the temperature range that could achieve both high bonding and good shape retention of the flow channel was evaluated. The methods for preparing the substrate and cover plate, and the specific method for bonding by heat fusion, were the same as in Example 1-1.

[0165] <Evaluation> The shape retention and bondability of the obtained microchannel chip were evaluated in the same manner as in Example 1-1. The results are shown in Table 6.

[0166]

[0167] Examples 3-1 to 3-6: Using the resins in the combinations shown in Table 7, a substrate and a cover plate with flow channels were prepared, and these were then bonded by heat fusion to obtain a microchannel chip. Three temperatures were used during bonding, ranging from 100 to 110°C in 5°C increments, to evaluate the temperature range that could achieve both high bonding and good shape retention of the flow channel. The method for preparing the substrate and the specific method for bonding by heat fusion were the same as in Example 1-1.

[0168] The cover plates were prepared as follows: Each resin was extruded and cast from a 30 mm diameter single-screw extruder equipped with a 160 mm wide T-die to obtain a 0.2 mm thick film, which was then cut into a 40 mm wide x 80 mm long piece to prepare a cover plate.

[0169] <Evaluation> The shape retention and bondability of the obtained microchannel chip were evaluated in the same manner as in Example 1-1. The results are shown in Table 7.

[0170]

[0171] Although Tables 6 and 7 show the results for the lowest bonding temperature of 100°C, it has been confirmed that the microchannel chip according to this embodiment can achieve both high bonding properties and good shape retention of the channel grooves even at temperatures below 100°C.

[0172] Although the present invention has been described in detail and with reference to specific embodiments, it will be apparent to those skilled in the art that various changes and modifications can be made without departing from the spirit and scope of the present invention. This application is based on a Japanese patent application (Patent Application No. 2024-053743) filed on March 28, 2024, the contents of which are incorporated herein by reference.

Claims

1. A microchannel chip comprising at least a substrate having a flow channel and a cover plate bonded to the substrate so as to cover the flow channel, wherein the substrate and the cover plate are each made of a thermoplastic resin, and the thermoplastic resin of at least one of the substrate and the cover plate contains, as a constituent, a block copolymer (A) that satisfies the following conditions (1-i) to (1-iii): (1-i) The block copolymer (A) contains an amorphous resin segment (A-a) having an alicyclic structure and an acyclic aliphatic low-crystalline resin segment (A-c). (1-ii) The glass transition temperature Tg(A) of the block copolymer (A) is in the range of 50 to 140°C. (1-iii) The glass transition temperature Tg(A) and the melting point Tm(A) of the block copolymer (A) satisfy the relationship of the following formula (1): Formula (1): Tg(A) - Tm(A) ≧ 20°C 2. A substrate having a flow channel for use in a microchannel chip, the substrate being made of a thermoplastic resin, the thermoplastic resin containing, as a constituent, a block copolymer (A)' that satisfies the following conditions (1-i)' to (1-iii)'. (1-i)' The block copolymer (A)' contains an amorphous resin segment (A-a)' having an alicyclic structure and an acyclic aliphatic low-crystalline resin segment (A-c)'. (1-ii)' The glass transition temperature Tg(A)' of the block copolymer (A)' is in the range of 50 to 140°C. (1-iii)' The glass transition temperature Tg(A)' and the melting point Tm(A)' of the block copolymer (A)' satisfy the relationship of the following formula (1)'. Formula (1)': Tg(A)' - Tm(A)' ≧ 20°C 3. A cover plate for a micro-channel chip, the cover plate being bonded to a substrate having a channel groove so as to cover the substrate, the cover plate being made of a thermoplastic resin, the thermoplastic resin containing, as a constituent, a block copolymer (A)'' that satisfies the following conditions (1-i)'' to (1-iii)''. (1-i)'' The block copolymer (A)'' contains an amorphous resin segment (A-a)'' having an alicyclic structure, and an acyclic aliphatic low-crystalline resin segment (A-c)''. (1-ii)'' The glass transition temperature Tg(A)'' of the block copolymer (A)'' is in the range of 50 to 140°C. (1-iii)'' The glass transition temperature Tg(A)'' and the melting point Tm(A)'' of the block copolymer (A)'' satisfy the relationship of the following formula (1)''. Formula (1)'': Tg(A)'' - Tm(A)'' ≧ 20°C 4. A microchannel chip comprising at least a substrate having a flow channel and a cover plate bonded to the substrate so as to cover the flow channel, wherein the substrate and the cover plate are each made of a thermoplastic resin, and the thermoplastic resin of at least one of the substrate and the cover plate contains, as constituent components, a block copolymer (A1) and a block copolymer (A2) that satisfy the following conditions (2-i) to (2-iv): (2-i) The block copolymer (A1) contains an amorphous resin segment (A1-a) having an alicyclic structure and an acyclic aliphatic low-crystalline resin segment (A1-c), and the block copolymer (A2) contains an amorphous resin segment (A2-a) having an alicyclic structure and an acyclic aliphatic low-crystalline resin segment (A2-c). (2-ii) The glass transition temperature Tg(A1) of the block copolymer (A1) and the glass transition temperature Tg(A2) of the block copolymer (A2) are each in the range of 50 to 140°C. (2-iii) The glass transition temperature Tg(A1) and melting point Tm(A1) of the block copolymer (A1), and the glass transition temperature Tg(A2) and melting point Tm(A2) of the block copolymer (A2) satisfy the relationship of the following formula (2-1): Formula (2-1): Tg(A1) - Tm(A1) ≧ 20°C, and Tg(A2) - Tm(A2) ≧ 20°C (2-iv) The glass transition temperature Tg(A1) of the block copolymer (A1) and the glass transition temperature Tg(A2) of the block copolymer (A2) satisfy the relationship of the following formula (2-2): Formula (2-2): Tg(A1) - Tg(A2) ≧ 5°C 5. A substrate having a flow channel for use in a microchannel chip, the substrate being made of a thermoplastic resin, the thermoplastic resin containing, as constituent components, a block copolymer (A1)' and a block copolymer (A2)' that satisfy the following conditions (2-i)' to (2-iv): (2-i) The block copolymer (A1)' contains an amorphous resin segment (A1-a)' having an alicyclic structure and an acyclic aliphatic low-crystalline resin segment (A1-c)', and the block copolymer (A2)' contains an amorphous resin segment (A2-a)' having an alicyclic structure and an acyclic aliphatic low-crystalline resin segment (A2-c)'. (2-ii) The glass transition temperature Tg(A1)' of the block copolymer (A1)' and the glass transition temperature Tg(A2)' of the block copolymer (A2)' are each in the range of 50 to 140°C. (2-iii) The glass transition temperature Tg(A1)' and melting point Tm(A1)' of the block copolymer (A1)', and the glass transition temperature Tg(A2)' and melting point Tm(A2)' of the block copolymer (A2)' satisfy the relationship of the following formula (2-1)'. Formula (2-1)': Tg(A1)'-Tm(A1)'≧20°C, and Tg(A2)'-Tm(A2)'≧20°C. (2-iv) The glass transition temperature Tg(A1)' of the block copolymer (A1)' and the glass transition temperature Tg(A2)' of the block copolymer (A2)' satisfy the relationship of the following formula (2-2)'. Formula (2-2)': Tg(A1)'-Tg(A2)'≧5°C.

6. A cover plate for use in a micro-channel chip, the cover plate being bonded to a substrate having a channel groove so as to cover the substrate, the cover plate being made of a thermoplastic resin, the thermoplastic resin containing, as constituent components, a block copolymer (A1)'' and a block copolymer (A2)'' that satisfy the following conditions (2-i)'' to (2-iv)'': (2-i)'' The block copolymer (A1)'' contains an amorphous resin segment (A1-a)'' having an alicyclic structure and an acyclic aliphatic low-crystalline resin segment (A1-c)''; and the block copolymer (A2)'' contains an amorphous resin segment (A2-a)'' having an alicyclic structure and an acyclic aliphatic low-crystalline resin segment (A2-c)''. (2-ii) The glass transition temperature Tg(A1)'' of the block copolymer (A1)'' and the glass transition temperature Tg(A2)'' of the block copolymer (A2)'' are each in the range of 50 to 140°C. (2-iii) The glass transition temperature Tg(A1)'' and the melting point Tm(A1)'' of the block copolymer (A1)'' and the glass transition temperature Tg(A2)'' and the melting point Tm(A2)'' of the block copolymer (A2)'' satisfy the relationship of the following formula (2-1)''. Formula (2-1)": Tg(A1)"-Tm(A1)"≧20°C, and Tg(A2)"-Tm(A2)"≧20°C. (2-iv)" The glass transition temperature Tg(A1)" of the block copolymer (A1)" and the glass transition temperature Tg(A2)" of the block copolymer (A2)" satisfy the relationship of the following formula (2-2)". Formula (2-2)": Tg(A1)"-Tg(A2)"≧5°C.

7. A microchannel chip comprising at least a substrate having a flow channel and a cover plate bonded to the substrate so as to cover the flow channel, wherein the substrate and the cover plate are each made of a thermoplastic resin, and the thermoplastic resin of at least one of the substrate and the cover plate contains, as constituent components, a block copolymer (A) and a block copolymer (B) that satisfy the following conditions (3-i) to (3-v): (3-i) The block copolymer (A) contains an amorphous resin segment (A-a) having an alicyclic structure and an acyclic aliphatic low-crystalline resin segment (A-c). (3-ii) The glass transition temperature Tg(A) of the block copolymer (A) is in the range of 50 to 140°C. (3-iii) The glass transition temperature Tg(A) and the melting point Tm(A) of the block copolymer (A) satisfy the relationship of the following formula (3-1). Formula (3-1): Tg(A) - Tm(A) ≧ 20°C. (3-iv) The block copolymer (B) contains an amorphous resin segment (Ba) having an aromatic hydrocarbon structure and an acyclic aliphatic low-crystalline resin segment (Bc). (3-v) The glass transition temperature Tg(A) of the block copolymer (A) and the glass transition temperature Tg(B) of the block copolymer (B) satisfy the relationship of the following formula (3-2): Formula (3-2): Tg(A) - Tg(B) ≧ 10°C.

8. A substrate having a flow channel for use in a microchannel chip, the substrate being made of a thermoplastic resin, the thermoplastic resin containing, as constituent components, a block copolymer (A)' and a block copolymer (B)' that satisfy the following conditions (3-i)' to (3-v)': (3-i) The block copolymer (A)' contains an amorphous resin segment (A-a)' having an alicyclic structure and an acyclic aliphatic low-crystalline resin segment (A-c). (3-ii) The glass transition temperature Tg(A)' of the block copolymer (A)' is in the range of 50 to 140°C. (3-iii) The glass transition temperature Tg(A)' and the melting point Tm(A)' of the block copolymer (A)' satisfy the relationship of the following formula (3-1)': Formula (3-1)': Tg(A)'-Tm(A)'≧20°C. (3-iv)' The block copolymer (B)' comprises an amorphous resin segment (Ba)' having an aromatic hydrocarbon structure, and an acyclic aliphatic low-crystalline resin segment (B-c)'. (3-v)' The glass transition temperature Tg(A)' of the block copolymer (A)' and the glass transition temperature Tg(B)' of the block copolymer (B)' satisfy the relationship of the following formula (3-2)'. Formula (3-2)': Tg(A)'-Tg(B)'≧10°C.

9. A cover plate for a micro-channel chip, the cover plate being bonded to a substrate having a channel groove so as to cover the substrate, the cover plate being made of a thermoplastic resin, the thermoplastic resin containing, as constituent components, a block copolymer (A)'' and a block copolymer (B)'' that satisfy the following conditions (3-i)'' to (3-v)''. (3-i) The block copolymer (A)'' contains an amorphous resin segment (A-a)'' having an alicyclic structure, and an acyclic aliphatic low-crystalline resin segment (A-c)''. (3-ii) The glass transition temperature Tg(A)'' of the block copolymer (A)'' is in the range of 50 to 140°C. (3-iii) The glass transition temperature Tg(A)'' and the melting point Tm(A)'' of the block copolymer (A)'' satisfy the relationship of the following formula (3-1)''. Formula (3-1)': Tg(A)'-Tm(A)'≧20°C. (3-iv)'The block copolymer (B)' comprises an amorphous resin segment (B-a)' having an aromatic hydrocarbon structure and an acyclic aliphatic low-crystalline resin segment (B-c)'. (3-v)'The glass transition temperature Tg(A)' of the block copolymer (A)' and the glass transition temperature Tg(B)' of the block copolymer (B)' satisfy the relationship of the following formula (3-2)'. Formula (3-2)': Tg(A)'-Tg(B)'≧10°C.

10. A microchannel chip comprising at least a substrate having a flow channel and a cover plate bonded to the substrate so as to cover the flow channel, wherein the substrate and the cover plate are each made of a thermoplastic resin, and the thermoplastic resin of at least one of the substrate and the cover plate contains, as constituent components, a block copolymer (A1), a block copolymer (A2), and a block copolymer (B) that satisfy the following conditions (4-i) to (4-vi): (4-i) The block copolymer (A1) contains an amorphous resin segment (A1-a) having an alicyclic structure and an acyclic aliphatic low-crystalline resin segment (A1-c), and the block copolymer (A2) contains an amorphous resin segment (A2-a) having an alicyclic structure and an acyclic aliphatic low-crystalline resin segment (A2-c). (4-ii) The glass transition temperature Tg(A1) of the block copolymer (A1) and the glass transition temperature Tg(A2) of the block copolymer (A2) are each in the range of 50 to 140° C. (4-iii) The glass transition temperature Tg(A1) and the melting point Tm(A1) of the block copolymer (A1), and the glass transition temperature Tg(A2) and the melting point Tm(A2) of the block copolymer (A2) satisfy the relationship of the following formula (4-1): Formula (4-1): Tg(A1) - Tm(A1) ≧ 20° C., and Tg(A2) - Tm(A2) ≧ 20° C. (4-iv) The glass transition temperature Tg(A1) of the block copolymer (A1) and the glass transition temperature Tg(A2) of the block copolymer (A2) satisfy the relationship of the following formula (4-2). Formula (4-2): Tg(A1) - Tg(A2) ≧ 5°C. (4-v) The block copolymer (B) contains an amorphous resin segment (Ba) having an aromatic hydrocarbon structure and an acyclic aliphatic low-crystalline resin segment (B-c). (4-vi) The glass transition temperature Tg(A2) of the block copolymer (A2) and the glass transition temperature Tg(B) of the block copolymer (B) satisfy the relationship of the following formula (4-3): Formula (4-3): Tg(A2) - Tg(B) ≧ 10°C.

11. A substrate having a flow channel for use in a microchannel chip, the substrate being made of a thermoplastic resin, the thermoplastic resin containing, as constituent components, a block copolymer (A1)', a block copolymer (A2)', and a block copolymer (B)' that satisfy the following conditions (4-i)' to (4-vi): (4-i) The block copolymer (A1)' contains an amorphous resin segment (A1-a)' having an alicyclic structure and an acyclic aliphatic low-crystalline resin segment (A1-c)', and the block copolymer (A2)' contains an amorphous resin segment (A2-a)' having an alicyclic structure and an acyclic aliphatic low-crystalline resin segment (A2-c)'. (4-ii) The glass transition temperature Tg(A1)' of the block copolymer (A1)' and the glass transition temperature Tg(A2)' of the block copolymer (A2)' are each in the range of 50 to 140°C. (4-iii) The glass transition temperature Tg(A1)' and melting point Tm(A1)' of the block copolymer (A1)', and the glass transition temperature Tg(A2)' and melting point Tm(A2)' of the block copolymer (A2)' satisfy the relationship of the following formula (4-1)': Formula (4-1)': Tg(A1)'-Tm(A1)'≧20°C, and Tg(A2)'-Tm(A2)'≧20°C. (4-iv) The glass transition temperature Tg(A1)' of the block copolymer (A1)' and the glass transition temperature Tg(A2)' of the block copolymer (A2)' satisfy the relationship of the following formula (4-2)'. Formula (4-2)': Tg(A1)'-Tg(A2)'≧5°C. (4-v)' The block copolymer (B)' comprises an amorphous resin segment (Ba)' having an aromatic hydrocarbon structure, and an acyclic aliphatic low-crystalline resin segment (B-c)'. (4-vi)' The glass transition temperature Tg(A2)' of the block copolymer (A2)' and the glass transition temperature Tg(B)' of the block copolymer (B)' satisfy the relationship of the following formula (4-3)'. Formula (4-3)': Tg(A2)'-Tg(B)'≧10°C.

12. A cover plate for use in a micro-channel chip, the cover plate being bonded to a substrate having a channel groove so as to cover the substrate, the cover plate being made of a thermoplastic resin, the thermoplastic resin containing, as constituent components, a block copolymer (A1)'', a block copolymer (A2)'', and a block copolymer (B)'' that satisfy the following conditions (4-i)'' to (4-vi): (4-i) The block copolymer (A1)'' contains an amorphous resin segment (A1-a)'' having an alicyclic structure and an acyclic aliphatic low-crystalline resin segment (A1-c)'', and the block copolymer (A2)'' contains an amorphous resin segment (A2-a)'' having an alicyclic structure and an acyclic aliphatic low-crystalline resin segment (A2-c)''. (4-ii) The glass transition temperature Tg(A1)'' of the block copolymer (A1)'' and the glass transition temperature Tg(A2)'' of the block copolymer (A2)'' are each in the range of 50 to 140°C. (4-iii) The glass transition temperature Tg(A1)'' and the melting point Tm(A1)'' of the block copolymer (A1)'' and the glass transition temperature Tg(A2)'' and the melting point Tm(A2)'' of the block copolymer (A2)'' satisfy the relationship of the following formula (4-1)''. Formula (4-1)": Tg(A1)"-Tm(A1)"≧20°C, and Tg(A2)"-Tm(A2)"≧20°C. (4-iv)" The glass transition temperature Tg(A1)" of the block copolymer (A1)" and the glass transition temperature Tg(A2)" of the block copolymer (A2)" satisfy the relationship of the following formula (4-2)". Formula (4-2)": Tg(A1)"-Tg(A2)"≧5°C. (4-v)" The block copolymer (B)" comprises an amorphous resin segment (Ba)" having an aromatic hydrocarbon structure, and an acyclic aliphatic low-crystalline resin segment (B-c)". (4-vi) The glass transition temperature Tg(A2)'' of the block copolymer (A2)'' and the glass transition temperature Tg(B)'' of the block copolymer (B)'' satisfy the relationship of the following formula (4-3)''. Formula (4-3)'': Tg(A2)''-Tg(B)''≧10°C 13. The microchannel chip according to claim 4 or 10, wherein the block copolymer (A1) and the block copolymer (A2) further satisfy the following condition (5): (5) The amorphous resin segment (A1-a) having an alicyclic structure and the amorphous resin segment (A2-a) having an alicyclic structure are each a vinylcyclohexane-based polymer, and the acyclic aliphatic low-crystalline resin segment (A1-c) and the acyclic aliphatic low-crystalline resin segment (A2-c) are each an ethylene-butene copolymer.

14. The microchannel chip according to claim 7 or 10, wherein the block copolymer (B) further satisfies the following condition (6): (6) The amorphous resin segment (Ba) having an aromatic hydrocarbon structure is a styrene-based polymer, and the acyclic aliphatic low-crystalline resin segment (Bc) is an ethylene-butene copolymer.

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